Pigmented villonodular synovitis (PVNS) is a rare proliferative disorder that affects synovium, tendon sheath and bursa. Although the condition can present in any joint, knee joint is the most commonly affected site and only 2.5% of cases occur in foot and ankle joint. PVNS occurs in two types: localized and diffuse. Localized type is characterized by focal involvement of the synovium with either nodular or pedunculated masses, Diffuse type affects virtually the entire synovium. Diffuse type has reported more recurrence rate. We have experienced a patient who has diffuse type PVNS of ankle joint and report an optimal method of surgical treatment.