Lisa Gerritsen's acting career spanned the years of 1968 to around 1977. Her introduction to acting was in a local summer parks department production when she was about 8. Soon afterward, she began pursuing a professional career. Encouraged by her mother and grandfather, veteran screenwriter True Boardman, she weathered the disappointments of numerous casting calls until she landed her first professional role in an episode of The Doris Day Show in 1968.
After The Doris Day Show, Lisa went on to guest-star in several TV shows including Bonanza, The Courtship of Eddie's Father, The Virginian (retitled The Men From Shiloh during the last season), and Family Affair to name just a few. She was also cast in several episodes of Gunsmoke, one of which helped her to land a regular role in the 1969 NBC comedy series "My World and Welcome to It" that starred William Windom and Joan Hotchkis.
In 1970, she was cast in her most notable role, Bess Lindstrom, in The Mary Tyler Moore show. She appeared in a total of 10 episodes until 1975. Lisa went on to reprise the role of Bess as a regular in the 1975-1977 spin-off series Phyllis.
Among her numerous TV appearances, she also was cast in several movies. She made her first big-screen appearance in the 1970 movie Airport playing the role of Libby Bakersfeld. Her most memorable movie role was as Linda in The War Between Men and Women (1972) that starred Jack Lemmon and Barbara Harris. She also starred in several other movies including A Howling in the Woods (1971), Locusts (1974), and Mixed Company (1974).