Physical exertion, sexual activity or trauma can precipitate cremasteric contraction and result in torsion of a testicle with an underlying congenital anomaly. A high index of suspicion is required by the primary care doctor if acute torsion is to be diagnosed early for immediate reduction. The duration of torsion and the degree of twisting determine the long-term salvage rate of testicular tissue. An aggressive policy of immediate exploration of the unilateral acute scrotum in young men resulted in exploration of twice as many cases of acute epididymitis as torsion of the testis or its appendages but also resulted in an immediate orchiopexy (salvage) rate of 90 per cent and a long-term salvage rate of 73 per cent of patients with acute torsion of the testis.