Arkin made his feature acting debut in "Chu Chu and the Philly Flash" (1981), a film dominated by Arkin's parents: his father starred and his stepmother Barbara Dana wrote the screenplay. That same year, Arkin starred in "Full Moon High", a likably silly werewolf high school comedy from horror auteur Larry Cohen. His film career never really took off, consisting of "Under the Rainbow", (1981), "Personal Foul" (1987), "The Doctor" (1991) and Todd Haynes' avant-garde short "Dottie Gets Spanked" (1993) starring Julie Halston. Arkin has also worked in NY theater ("Guys and Dolls" on Broadway; "Sight Unseen" and "Four Dogs and a Bone" off-Broadway).
The 1980s and '90s provided many stints on TV for Arkin: the series "Teachers Only" (NBC, 1982); "Tough Cookies" (CBS, 1986); "A Year in the Life" (NBC, 1987-88); and "Big Wave Dave's" (CBS, 1993); and such TV-movies and miniseries as "Heat Wave" (TNT, 1990); "Babies" (NBC, 1990); and "In the Line of Duty: Hunt for Justice" (NBC, 1995).
Arkin received acclaim and exposure in the recurring role of Adam, the reputedly feral, reclusive, and antagonistic eccentric ex-gourmet chef on "Northern Exposure" (CBS, 1990-94). The character began as a local variation of Bigfoot and evolved into an (uneasily) integrated member of the community. Arkin joined the outstanding ensemble on the medical series "Chicago Hope" (CBS, 1994-2000) as Dr. Aaron Schutt, a neurosurgeon. Arkin successfully transitioned back and forth between the big and small screens, with seveval television movies to his credit, most notably as a detective opposite William H. Macy in "A Slight Case of Murder" (1999), and several supporting roles in features. He appeared in the horror thrillers "Halloween H20" (1998) and the David E. Kelley-penned "Lake Placid" (1999), and was cast as Meg Ryan's husband in the Nora Ephron comedy "Hanging Up" (2000). Further roles followed, and he was especially winning as Eva Mendes' tabloid editor in the romantic comedy "Hitch" (2005).
Continuing his presence on series television, Arkin made a rare misstep when he took on the role of the father in the universally panned, short-lived talking infant sit-com "Baby Bob" (CBS, 2002), and he enjoyed recurring roles as the president's physician-confidante Dr. Stanley Keyworth in "The West Wing" beginning in 2000, and as Principal Ed Gibbs on the hit ABC sitcom "8 Simple Rules... for Dating My Teenage Daughter" starting in 2004.