diff --git a/app/services/import_csv/preprocess_milestones_service.rb b/app/services/import_csv/preprocess_milestones_service.rb
index 97fb381c58e07cd13176744f788fa574b632b29b..295c76184d3e7fca5650c54437acdb1edb9cfff6 100644
--- a/app/services/import_csv/preprocess_milestones_service.rb
+++ b/app/services/import_csv/preprocess_milestones_service.rb
@@ -14,8 +14,9 @@ def initialize(user, project, provided_titles)
     attr_reader :user, :project, :provided_titles, :results, :milestone_errors
 
     def execute
-      available_milestones = find_milestones_by_titles
-      return ServiceResponse.success if provided_titles.sort == available_milestones.sort
+      result = find_milestones_by_titles
+      available_milestones = result.map(&:title).uniq.sort
+      return ServiceResponse.success(payload: result) if provided_titles.sort == available_milestones
 
       milestone_errors[:missing][:header] = 'Milestone'
       milestone_errors[:missing][:titles] = provided_titles.difference(available_milestones) || []
@@ -29,7 +30,7 @@ def find_milestones_by_titles
         title: provided_titles
       }
       finder_params[:group_ids] = project.group.self_and_ancestors.select(:id) if project.group
-      MilestonesFinder.new(finder_params).execute.map(&:title).uniq
+      MilestonesFinder.new(finder_params).execute
     end
   end
 end
diff --git a/app/services/issuable/import_csv/base_service.rb b/app/services/issuable/import_csv/base_service.rb
index 95338374ca6b0a9088002661ced7b7538ed4dc62..c26fb016f79ecb73f6ac8b69039394aef2e44cea 100644
--- a/app/services/issuable/import_csv/base_service.rb
+++ b/app/services/issuable/import_csv/base_service.rb
@@ -12,7 +12,8 @@ def attributes_for(row)
         {
           title: row[:title],
           description: row[:description],
-          due_date: row[:due_date]
+          due_date: row[:due_date],
+          milestone_id: find_milestone_by_title(row[:milestone])
         }
       end
 
@@ -34,13 +35,20 @@ def preprocess_milestones!
         # Pre-Process Milestone if header is present
         return unless csv_data.lines.first.downcase.include?('milestone')
 
-        provided_titles = with_csv_lines.filter_map { |row| row[:milestone]&.strip&.downcase }.uniq
+        provided_titles = with_csv_lines.filter_map { |row| row[:milestone]&.strip }.uniq
         result = ::ImportCsv::PreprocessMilestonesService.new(user, project, provided_titles).execute
+        @available_milestones = result.payload
         return if result.success?
 
         # collate errors here and throw errors
         results[:preprocess_errors][:milestone_errors] = result.payload
       end
+
+      def find_milestone_by_title(title)
+        return unless title
+
+        @available_milestones.find { |milestone| milestone.title == title.to_s.strip } if @available_milestones
+      end
     end
   end
 end
diff --git a/ee/spec/services/ee/issues/import_csv_service_spec.rb b/ee/spec/services/ee/issues/import_csv_service_spec.rb
index 1f08aa919615d628581e24ff130e08341115e616..ce28126b8356450c51fed5994697ea2535b9c2da 100644
--- a/ee/spec/services/ee/issues/import_csv_service_spec.rb
+++ b/ee/spec/services/ee/issues/import_csv_service_spec.rb
@@ -14,6 +14,8 @@
     described_class.new(user, project, uploader)
   end
 
+  let!(:test_milestone) { create(:milestone, project: project, title: '15.10') }
+
   describe '#execute' do
     subject { service.execute }
 
diff --git a/spec/fixtures/csv_complex.csv b/spec/fixtures/csv_complex.csv
index 60d8aa5d6f75ecd5729fb5e20a4a012539966ae3..b42a5e99d88198529ac3a6882f45fdca30cad959 100644
--- a/spec/fixtures/csv_complex.csv
+++ b/spec/fixtures/csv_complex.csv
@@ -1,6 +1,6 @@
-title,description,due date
+title,description,due date,milestone
 Issue in 中文,Test description,
 "Hello","World",
 "Title with quote""","Description
 /assign @csv_assignee
-/estimate 1h",2022-06-28
+/estimate 1h",2022-06-28,15.10
diff --git a/spec/fixtures/csv_gitlab_export.csv b/spec/fixtures/csv_gitlab_export.csv
index 65422509eef4a4b7a43446acb1f6885af7050343..a39260f9dfffb0b393a839faa22c6f61c1216a0e 100644
--- a/spec/fixtures/csv_gitlab_export.csv
+++ b/spec/fixtures/csv_gitlab_export.csv
@@ -2,4 +2,4 @@ Issue ID,URL,Title,State,Description,Author,Author Username,Assignee,Assignee Us
 1,http://localhost:3000/jashkenas/underscore/issues/1,Title,Open,,Elva Jerde,jamel,Tierra Effertz,aurora_hahn,No,No,,2020-01-17 10:36:26,2020-02-19 10:36:26,,v1.0,,"Brene,Cutlass,Escort,GVM",0,0,,
 3,http://localhost:3000/jashkenas/underscore/issues/3,Nihil impedit neque quos totam ut aut enim cupiditate doloribus molestiae.,Open,Omnis aliquid sint laudantium quam.,Marybeth Goodwin,rocio.blanda,Annemarie Von,reynalda_howe,No,No,,2020-01-23 10:36:26,2020-02-19 10:36:27,,v1.0,,"Brene,Cutlass,Escort,GVM",0,0,,
 34,http://localhost:3000/jashkenas/underscore/issues/34,Dismiss Cipher with no integrity,Open,,Marybeth Goodwin,rocio.blanda,"","",No,No,,2020-02-19 10:38:49,2020-02-19 10:38:49,,,,,0,0,,
-35,http://localhost:3000/jashkenas/underscore/issues/35,Test Title,Open,Test Description,Marybeth Goodwin,rocio.blanda,"","",No,No,,2020-02-19 10:38:49,2020-02-19 10:38:49,,,,,0,0,,
+35,http://localhost:3000/jashkenas/underscore/issues/35,Test Title,Open,Test Description,Marybeth Goodwin,rocio.blanda,"","",No,No,,2020-02-19 10:38:49,2020-02-19 10:38:49,,v1.0,,,0,0,,
diff --git a/spec/services/issues/import_csv_service_spec.rb b/spec/services/issues/import_csv_service_spec.rb
index 660686cf805c2baf22661905d3de261fd76b99bd..d3d7277e3e379e5bb9db25d29f6231487059c44b 100644
--- a/spec/services/issues/import_csv_service_spec.rb
+++ b/spec/services/issues/import_csv_service_spec.rb
@@ -14,6 +14,8 @@
     described_class.new(user, project, uploader)
   end
 
+  let!(:test_milestone) { create(:milestone, project: project, title: '15.10') }
+
   include_examples 'issuable import csv service', 'issue' do
     let(:issuables) { project.issues }
     let(:email_method) { :import_issues_csv_email }
@@ -36,7 +38,8 @@
           description: 'Description',
           time_estimate: 3600,
           assignees: include(assignee),
-          due_date: Date.new(2022, 6, 28)
+          due_date: Date.new(2022, 6, 28),
+          milestone_id: test_milestone.id
         )
       )
     end
diff --git a/spec/support/shared_examples/services/issuable/issuable_import_csv_service_shared_examples.rb b/spec/support/shared_examples/services/issuable/issuable_import_csv_service_shared_examples.rb
index 8a3ab07bbfe803b2debb5f36051eceb6e4bf6c18..aa31bd2b60410f132cc1792a6f2be47557fdbfcb 100644
--- a/spec/support/shared_examples/services/issuable/issuable_import_csv_service_shared_examples.rb
+++ b/spec/support/shared_examples/services/issuable/issuable_import_csv_service_shared_examples.rb
@@ -30,7 +30,7 @@
 
     context 'with a file generated by Gitlab CSV export' do
       let(:file) { fixture_file_upload('spec/fixtures/csv_gitlab_export.csv') }
-      let!(:test_milestone) { create(:milestone, project: project, title: 'v1.0') }
+      let_it_be(:test_milestone) { create(:milestone, project: project, title: 'v1.0') }
 
       it 'imports the CSV without errors' do
         expect(subject[:success]).to eq(4)
@@ -41,7 +41,19 @@
       it 'correctly sets the issuable attributes' do
         expect { subject }.to change { issuables.count }.by 4
 
-        expect(issuables.reload).to include(have_attributes({ title: 'Test Title', description: 'Test Description' }))
+        if issuable_type == 'issue'
+          expect(issuables.reload).to include(
+            have_attributes({ title: 'Test Title', description: 'Test Description', milestone_id: test_milestone.id }),
+            have_attributes({ title: 'Title', milestone_id: test_milestone.id }),
+            have_attributes(
+              { title: 'Nihil impedit neque quos totam ut aut enim cupiditate doloribus molestiae.',
+                description: 'Omnis aliquid sint laudantium quam.',
+                milestone_id: test_milestone.id })
+          )
+
+        else
+          expect(issuables.reload).to include(have_attributes({ title: 'Test Title', description: 'Test Description' }))
+        end
       end
 
       it_behaves_like 'importer with email notification'