In an April 24 2008 Newark Star Ledger interview, the writers Jon Hurwitz and Hayden Schlossberg mention that Kumar's poem "The Square Root of Three" (parody of Joyce Kilmer's Trees) was written by a classmate of theirs, David Feinberg when all three went to Randolph High School in New Jersey. They were happy they could include in the film a poem they loved while growing up, and Feinberg was thrilled to make a contribution to the film.
According to Hollywood Reporter (27 April 2008 issue), Warner Bros' distribution president Dan Fellman said this movie was originally produced as a straight-to-video movie until a decision was made to release it theatrically.
Amnesty International USA was highly critical of the film's satirical depiction of the Guantanamo Bay Detention Camp, commenting on their website that "Guantanamo is no joke." The organization's membership was encouraged to hand out fliers and fact sheets at theatrical screenings to bring attention to the alleged human rights abuses that have occurred at the camp.
In the beginning of the film, Kumar tells Harold that their Amsterdam trip is going to be 'Exactly like Eurotrip only it's not going to suck'. The 'Amsterdam' scenes in Eurotrip (2004) were mostly filmed in Eastern Europe, while the scenes in Amsterdam at the ending of Harold & Kumar Escape from Guantanamo Bay were filmed on location in The Netherlands.