diff --git a/CHANGES.rst b/CHANGES.rst
index cdedab46306ca16728781617b449936fea899ee5..522047db6f216a50f343c08d0d346329a51131a8 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -178,6 +178,9 @@ Smart Rollup node
   enabled with the flag ``--enable-performance-metrics`` (requires
   ``lsof``). (MR :gl:`!12290`)
 
+- Addition of ``elapsed_time`` to performance metrics,
+  which exposes in seconds the time since the node started. (MR :gl:`!16551`)
+
 - Rotate multiple batcher keys in injector so that they are used evenly. (MR
   :gl:`!14194`)
 
diff --git a/etherlink/CHANGES_NODE.md b/etherlink/CHANGES_NODE.md
index f4512cf93526b23848c8f89afc68f83af47c3105..9ee3e37983f6add55f906cb56422f6bc5450f2b8 100644
--- a/etherlink/CHANGES_NODE.md
+++ b/etherlink/CHANGES_NODE.md
@@ -18,6 +18,8 @@
   "history": { "mode": "rolling", "retention": 14 }
   ```
   (!16465)
+- Addition of `elapsed_time` to performance metrics, which exposes in seconds the time since the node
+  started. (!16551)
 
 #### UX
 
diff --git a/etherlink/tezt/tests/expected/evm_rollup.ml/EVM node- list metrics regression.out b/etherlink/tezt/tests/expected/evm_rollup.ml/EVM node- list metrics regression.out
index e354a207217dd6ab4e54105b999b7f8c33178bb6..439a2f691f50e26b122137c5698fc152b5b5f5b4 100644
--- a/etherlink/tezt/tests/expected/evm_rollup.ml/EVM node- list metrics regression.out	
+++ b/etherlink/tezt/tests/expected/evm_rollup.ml/EVM node- list metrics regression.out	
@@ -32,6 +32,8 @@
 #TYPE octez_evm_node_performance_data gauge
 #HELP octez_evm_node_performance_disk_percentage Disk Usage Percentage
 #TYPE octez_evm_node_performance_disk_percentage gauge
+#HELP octez_evm_node_performance_elapsed_time Number of seconds since the node is running
+#TYPE octez_evm_node_performance_elapsed_time counter
 #HELP octez_evm_node_performance_file_descriptors Open file descriptors
 #TYPE octez_evm_node_performance_file_descriptors gauge
 #HELP octez_evm_node_performance_logs Disk usage: daily_logs
diff --git a/prometheus/src/prometheus.ml b/prometheus/src/prometheus.ml
index 3ad76b78244c4b80592b63d815f8fbd4da212f77..c25cd306dbdde57bfce7f1259cd2d947d2baa7a9 100644
--- a/prometheus/src/prometheus.ml
+++ b/prometheus/src/prometheus.ml
@@ -288,6 +288,10 @@ module Counter = struct
   let inc t v =
     assert (v >= 0.0) ;
     t := !t +. v
+
+  let set t v =
+    assert (v >= !t) ;
+    t := v
 end
 
 module Gauge = struct
diff --git a/prometheus/src/prometheus.mli b/prometheus/src/prometheus.mli
index f8bae5a1c20cfc8498699d7a33affd6bd4ef02a3..d146eb0fc048aa9105a0fcb615b53467dac67211 100644
--- a/prometheus/src/prometheus.mli
+++ b/prometheus/src/prometheus.mli
@@ -166,6 +166,9 @@ module Counter : sig
 
   (** [inc t v] increases [t] by [v], which must be non-negative. *)
   val inc : t -> float -> unit
+
+  (** [set t v] sets the current value of the counter to [v]. *)
+  val set : t -> float -> unit
 end
 
 (** A gauge is a metric that represents a single numerical value that can arbitrarily go up and down. *)
diff --git a/src/lib_performance_metrics/octez_performance_metrics.ml b/src/lib_performance_metrics/octez_performance_metrics.ml
index aabebec72221c4f579b474095b2d40d3bad3934f..0a9bc2053693e7fa14cc06a3233764c82fb2e329 100644
--- a/src/lib_performance_metrics/octez_performance_metrics.ml
+++ b/src/lib_performance_metrics/octez_performance_metrics.ml
@@ -53,6 +53,10 @@ let supports_performance_metrics () =
 module Make (R : REGISTRY) = struct
   include R
 
+  let start_time = Time.System.now ()
+
+  let v_counter = Counter.v ~registry ~namespace ~subsystem
+
   let v_gauge = Gauge.v ~registry ~namespace ~subsystem
 
   let virtual_ = v_gauge ~help:"Size Memory Stats" "performance_virtual"
@@ -63,6 +67,11 @@ module Make (R : REGISTRY) = struct
 
   let cpu = v_gauge ~help:"CPU Percentage" "performance_cpu_percentage"
 
+  let elapsed_time =
+    v_counter
+      ~help:"Number of seconds since the node is running"
+      "performance_elapsed_time"
+
   let get_ps pid =
     Lwt.catch
       (fun () ->
@@ -224,8 +233,15 @@ module Make (R : REGISTRY) = struct
         Gauge.set connections @@ Float.of_int conn)
       r
 
+  let set_elapsed_time () =
+    let new_elapsed_time =
+      Ptime.Span.to_float_s @@ Ptime.diff (Time.System.now ()) start_time
+    in
+    Counter.set elapsed_time new_elapsed_time
+
   let set_stats ~data_dir =
     let open Lwt_syntax in
+    set_elapsed_time () ;
     let* () = set_memory_cpu_stats ()
     and* () = set_disk_usage_stats ~data_dir
     and* () = set_file_descriptors () in
diff --git a/tezt/tests/expected/sc_rollup.ml/Smart rollup node- list metrics regression (with performance metrics).out b/tezt/tests/expected/sc_rollup.ml/Smart rollup node- list metrics regression (with performance metrics).out
index 6211dc7269cb1f349aed45b394871d67e3b0f513..b45c7b7b9f117fe10676c2ff4c3f541022d1ad83 100644
--- a/tezt/tests/expected/sc_rollup.ml/Smart rollup node- list metrics regression (with performance metrics).out	
+++ b/tezt/tests/expected/sc_rollup.ml/Smart rollup node- list metrics regression (with performance metrics).out	
@@ -76,6 +76,8 @@
 #TYPE octez_sc_rollup_node_performance_data gauge
 #HELP octez_sc_rollup_node_performance_disk_percentage Disk Usage Percentage
 #TYPE octez_sc_rollup_node_performance_disk_percentage gauge
+#HELP octez_sc_rollup_node_performance_elapsed_time Number of seconds since the node is running
+#TYPE octez_sc_rollup_node_performance_elapsed_time counter
 #HELP octez_sc_rollup_node_performance_file_descriptors Open file descriptors
 #TYPE octez_sc_rollup_node_performance_file_descriptors gauge
 #HELP octez_sc_rollup_node_performance_logs Disk usage: daily_logs