Pigmented villonodular synovitis (PVNS) is a relatively rare disease affecting synovium-lined joints. PVNS was first fully described in 1941 by Jaffe et al, who considered it a benign inflammatory state of the synovium of uncertain etiology. Reports of this disease in the temporomandibular joint (TMJ) are extremely rare. This report describes a case of a 78-year-old man affected by PVNS of the right TMJ. Clinical examination revealed the presence of a right-sided preauricular mass; a magnetic resonance imaging scan showed a mass located lateral to the right mandibular condyle, close to the TMJ capsule. The clinical and pathologic features of the case are described. Keywords: pigmented villonodular synovitis, temporomandibular joint diseases