Despite not having previously sung professionally, Drysdale was invited to tour Australia with Ray Brown & The Whispers. She was then offered a recording contract and appeared in 26 episodes of the ABC's Dig We Must. Drysdale's popularity led to an invitation to perform for the troops in Vietnam for three weeks in late 1967, along with Patti Newton, the Strangers, and Doug Owen. In 1969, she went to the Far East to entertain American troops. In 1974, she became Ernie Sigley's barrel girl on The Ernie Sigley Show. It was here she gained the nickname Ding Dong. In 1975, Drysdale won the TV Week Gold Logie for the Most Popular Female Personality on Australian TV.
She won her second Gold Logie the following year. In the same period, she also won consecutive Silver Logies. Over the years, Drysdale has appeared regularly on numerous television shows including: The Norman Gunston Show, Celebrity Squares, Young Talent Time, Countdown,Division 4, Homicide and Bellbird. Drysdale has also worked in regional television in Victoria including guest appearances on BTV-6 Ballarat and hosting a morning magazine show on GLV-8 in the 1980s. As an actress, she has appeared in the movies, The Last of the Knucklemen, Snapshot, and Blowing Hot and Cold. In 2005, Channel 9 chose Denise as one of the most 50 important people on television for the last 50 years.