The daughter of Sol Lasser, who wrote an annual tax guide for civilians, the red-haired actress first won notice in 1962 replacing Barbra Streisand in the show-stopping role of Miss Marmelstein in the Broadway musical "I Can Get It For You Wholesale". Her subsequent stage appearances included "The Third Ear" (1964), an improvisational revue written and staged by the legendary Elaine May, and singing at such Greenwich Village haunts as The Bitter End. Lasser made her film debut in "What's New Pussycat?" (1965), scripted by and starring Woody Allen whom she married in 1966. Together they wrote the English dialogue dubbed over a Japanese film in "What's Up Tiger Lily?" (1966). Like other women in Allen's life, she co-starred with him in several of his early films, notably "Take the Money and Run" "Bananas" (1971), and "Everything You Wanted to Know About Sex* (*but were afraid to ask)" (1972). Despite a fine comic turn in "Slither" (1973), she was off the big screen until a 1980 reunion with Allen playing a small role as a secretary in "Stardust Memories". Her film appearances in the 80s and 90s were infrequent and generally in small character parts in efforts like the mother of a talented teenager in "Sing" (1989), a hippie in "Rude Awakening" (also 1989) and a kooky fortune teller in "Sudden Manhattan" (1997). An exception was her turn as Ben Gazarra's wife in "Happiness" (1998).
Despite seemingly walking away from her small screen success as Mary Hartman, Lasser continued to appear in memorable guest appearances and the occasional TV-movie. Often cast as neurotics, apologetics or just plain exasperating characters, the actress offered strong turns as Judd Hirsch's ex-wife on "Taxi" in 1980 and 1982, as Ed Begley Jr.'s bungling aunt on "St. Elsewhere" in 1982 and 1984, and as a woman who wreaks havoc in the life of Richard Mulligan on "Empty Nest" (NBC, 1992). Although Lasser was painfully thin in her youthful days, as she matured, she grew fuller of figure. Her best recalled longform work was as the female lead opposite small-town sheriff Alan Alda in "Isn't It Shocking?" (ABC, 1973) and as a gabby and daffy New Yorker going cross country with Charles Grodin in "Just Me and You" (NBC, 1978), which she also scripted. Lasser also found a secondary career as an acting teacher in NYC.