A curly-haired, angst-ridden American comedian and actor, Reiser first gained attention as Modell, one of the diner patrons in Barry Levinson's sleeper "Diner" (CBS, 1983). He later reprised the role for the 1983 TV pilot "Diner", but did not get a crack at sitcom stardom until "My Two Dads" (NBC, 1987-89), in which he starred as one of two possible fathers of an illegitimate daughter. Reiser went on to co-create, co-produce and co-write the theme for the TV series "Mad About You" (NBC, 1992-99).

Among Reiser's feature credits are "Beverly Hills Cop" (1984) and its sequel "Beverly Hills Cop II" (1987), a memorable villainous turn in James Cameron's "Aliens" (1986) and "Crazy People" (1990) as an agency executive trying to help a colleague (Dudley Moore) who has been institutionalized for promoting truth in advertising. He ventured back into features with a starring role in the romantic comedy "Mr. Write" (1994), playing a comedy writer who tries to win the affections of Jessica Tuck, and "Bye Bye, Love" (1995), an ensemble comedy about men coping with divorce.