She was known for her many roles in Warner Brothers (WB) television series, including 77 Sunset Strip, Hawaiian Eye, Surfside 6, Maverick, Bourbon Street Beat, Colt .45, and Bronco, but also did multiple episodes of Perry Mason and My Three Sons.

Elhardt performed six songs,[7] and was judged by the Los Angeles Times reviewer "A winsome and spirited young actress", who "displayed dramatic talent and a voice of appealing caliber".

She again received high marks for this production from the Los Angeles Times: "Kaye Elhardt, possessor of a lovely lyric voice... not only sings with taste and charm, but she is an unusually talented actress".

She was featured on Family Affair; Highway Patrol with Broderick Crawford; Wagon Train with Ward Bond; Sea Hunt with Lloyd Bridges; seven different roles in 77 Sunset Strip with Efrem Zimbalist, Jr.; Bourbon Street Beat with Andrew Duggan, Richard Long, and Van Williams; Bat Masterson with Gene Barry; My Three Sons with Fred MacMurray; The Tab Hunter Show with Tab Hunter; Surfside Six with Troy Donahue and Van Williams; Hawaiian Eye with Robert Conrad; Bronco; Yancy Derringer with Jock Mahoney; Colt .45; Philip Marlowe with Philip Carey; and more than a score of others.

All through college and most of her acting career, Elhardt lived with her parents in the Kentner Canyon area, north of Sunset Boulevard in Brentwood, Los Angeles.