A woman in Medicine Hat complained last year that Gary Bourdon, 58, committed the offence while she was face town on a table.
The woman testified that when she turned her head to look, she saw Bourdon had his genitals exposed and that he was masturbating.
Bourdon will have to undergo a risk assessment and a pre-sentence report has been ordered.
Bourdon has continued to work under the condition that a female chaperone be present in the room when he's with a female patient.
His sentence will be handed down Oct. 18.