The first of these later films was Sex Kittens Go to College (1960), which co-starred Tuesday Weld. Following the completion of the Argentine film The Blonde from Buenos Aires (1961), Van Doren took time off from her career. She came back in The Candidate (1964), soon followed by Freddy in the Wild West, both of which were low-budget films that left little impact. In 1964, Tommy Noonan convinced Van Doren to appear in 3 Nuts in Search of a Bolt. Van Doren had turned down Noonan's previous offer to star opposite Jayne Mansfield in Promises! Promises!, and was replaced with Marie McDonald. In 3 Nuts in Search of a Bolt, Mamie did a beer-bath scene but is not seen nude. She posed for Playboy to promote the film.
In 1964, Van Doren was a guest at the Whisky a Go Go on the Sunset Strip in West Hollywood, California when The Beatles were at the club visiting with Jayne Mansfield, and an inebriated George Harrison accidentally threw his drink on her when trying to throw it on some bothersome journalists. During the Vietnam War, she did tours for U.S. troops in Vietnam for three months in 1968, and again in 1970. In addition to USO shows, she visited hospitals, including the wards of amputees and burn victims.