The Sixties' pin-up, who became the magazine's Playmate of the Year in 1968, was arrested after allegedly firing a handgun at her partner during a fight at their Hollywood apartment.
The unidentified lover was admitted to hospital and is expected to make a full recovery.
Dorian was placed on $1 million (£667,000) bail and appeared before a judge on Wednesday (20Oct10), when she entered her plea, reports TMZ.com.
The 66 year old maintains her boyfriend was shot by a drug dealer.
The ex-model, who is still in police custody, must return to court next month (Nov10). If convicted, she faces life behind bars.