Polyarteritis nodosa is a systemic vasculitis characterized by segmental necrotizing lesions of medium and small-size arteries. Rarely, the inflammatory process is isolated and involves a single organ without systemic manifestations. We describe a patient with isolated polyarteritis nodosa of the testis who presented with a testicular mass mimicking primary testicular tumor. The postoperative laboratory evaluation was negative. Long-term follow-up, without systemic treatment, showed no evidence of recurrence in the remainder of the testis or development of systemic vasculitis.