Objective: The main purpose of this study was to evaluate the effects of virgin olive oil phonophoresis on female athletes' anterior knee pain (AKP). Materials and Methods: A double blinded randomized clinical trial was conducted. Ninety-three female athletes suffering from AKP voluntarily participated in this study. Patients were randomly assigned into olive oil (n=31), piroxicam (n=31) or base gel phonophoresis (n=31) groups. At the baseline visit, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire was filled by subjects who were then treated with olive oil, piroxicam or pure phonophoresis for 12 sessions. After 6 and 12 sessions of physiotherapy, subjects filled the questionnaire again. Main outcomes were significant improvement in pain, stiffness, physical function, and total WOMAC scores. Results: Although, there was a significant reduction in symptoms of AKP at the end of the therapy in all groups (p< 0.05), but in olive oil group, this improvement was seen after 6 sessions of treatment (p< 0.001). A significant difference between olive oil group and piroxicam and/or phonophoresis group was observed after 6 sessions of therapy (p< 0.05). Conclusion: It could be proposed that phonophoresis with virgin olive oil is as effective as piroxicam gel on lowering WOMAC scores of AKP in female athletes and also has several beneficial properties including faster effect and shorter duration of therapy. The exact mechanism of beneficial action of virgin olive oil on AKP is not clear and requires further studies.