Zee was a professional model who reportedly worked for the prestigious Wilhelmina Agency in the 1970s. She also did nude modeling and later decided to move into pornographic films. She starred or appeared in over 300 adult movies since entering the industry in around 1986. She was about 35 years old when she began, an age when many adult actresses are already retired. She typically played what would later be called MILF or "cougar" roles.
"I am an exhibitionist, so to take it to the nth degree was obviously where I was going. It took me a little longer to get there than some women but I knew I could be one of the best actresses in adult films, if not the best," she said in an interview. For sixty-seven films and videos she served as director, writer and producer. She also had her own namesake production company, Ona Zee Pictures.
During the 1990s she formed a pornographic actors union, but it ultimately collapsed due to lack of political and legal support. She has since retired from the industry and become a realtor.