Twenty-nine children with familial Mediterranean fever presented with 39 attacks of acute scrotal pain. Of these, 25 patients had an acute scrotum complicating familial Mediterranean fever and only four had testicular torsion. Scrotal pain was the only manifestation of a familial Mediterranean fever crisis in 36 episodes and in 15 boys scrotal involvement was the first manifestation of the condition. Fourteen patients were treated medically. Of 15 patients who underwent scrotal exploration there were no definite diagnostic findings in 11 and four had testicular torsion. Three cardinal features strongly suggest the diagnosis of acute scrotum in familial Mediterranean fever in a boy of Mediterranean origin with a relevant family history: recurrent scrotal pain or swelling; body temperature above 37.5 degrees C; and gradual onset of pain, usually of more than 12 h duration. Conservative management can safely be undertaken in these boys without fear of losing a salvageable testis.