Some of the interior New York hotel scenes were filmed in Los Angeles at the old Bullocks Wilshire Building, which is no longer open. Others were also filmed at the Dorchester Hotel in London.
Rupert Everett was offered the role of Lord Rutledge because some of the movie was shot in London and director Ken Kwapis wanted at least one British actor in the cast as a result. Everett at first thought the script was silly but agreed ultimately to participate because he didn't have a lot of success in his career at the time and he was also a fan of Seinfeld (1989) and thought the movie would be a hit with Jason Alexander in the lead.
Jason Alexander was always the first choice for the role of Robert Grant but because Seinfeld (1989) was in the middle of filming its sixth season, and because part of the movie would be filmed in London, he almost had to turn down the role. In the meanwhile, Dan Aykroyd, Bill Murray, Ted Danson, Chevy Chase, Steve Martin, Robin Williams, Tom Hanks, Rowan Atkinson, and John Stamos were all considered as alternatives in case Alexander was unavailable. Fortunately, director Ken Kwapis arranged for all of the exterior scenes that were shot in Los Angeles to be filmed at the same time as Seinfeld (1989), which was also filmed in Los Angeles, while the London interior sequences would be filmed during Alexander's summer hiatus from the show.
Director Ken Kwapis asked Clint Eastwood to cameo as Mr. Dubrow as a in-joke to his films Every Which Way But Loose (1978) and Any Which Way You Can (1980), which were also about orangutans. Eastwood however wanted far too much money for the appearance and was therefore passed over.