Tommy mentioned in a Q&A that due to too much material being shot, they had to split Best F(r)iends into two volumes.
The film's June (2018) Fathom Events release featured an advance preview cut. The final cut of the film premiered at 2018's Beyond Fest in Los Angeles, California.
The casting of Paul Scheer as Malmo came about after Scheer had Greg Sestero as a guest on his podcast "How Did This Get Made", and striking up an aquantance with both Sestero and Tommy Wiseau.
Many of the desert scenes were shot in Texas Canyon near Benson, ArIzona which is famous for its rock formations. The production had to get special permission to shoot at the site.