To evaluate the impact on testicular function of the surgical approach used to treat testicular torsion.Seventeen males operated on for testicular torsion at a median age of 14 years were investigated. Serum follicle-stimulating hormone (FSH), testosterone and inhibin B as well as testicular volume were measured early (median 36 days) and/or late (median 1.1 years) after operation.Orchiectomy was performed in six, and testicular detorsion and orchiopexy in 11 patients. The duration of the preoperative symptoms in the detorsion group was 15h (range 6–168) and in the orchiectomy group 42h (range 24–96) (P=0.03). Preoperative colour Doppler ultrasonography showed some circulation in 40% of the patients. At 1 month the median serum inhibin B level was significantly higher after preserving surgery (P=0.01). At 1 year postoperatively, the median serum FSH level tended to be lower after testicular preservation (P=0.09). Abnormal inhibin B or FSH values were observed in 35% of the patients.Testicular function is often compromised in patients with testicular torsion. Testis-preserving surgery yields better testicular function than orchiectomy in the short term if the testis is not obviously necrotic. Testicular torsion does not necessarily cause the circulation to cease completely, and preserving surgery can also sometimes be attempted after delayed diagnosis.