Antisperm antibodies were studied in 44 patients with less than 14 years of age, with unilateral testicle torsion and other testicular pathologies with vascular and inflammatory processes. The clinical and evolution of testicular size after one year of initial evaluation were obtained. Four cases had positive antisperm antibodies: One testicular torsion, two acute orchitis and one varicocele. In all the cases including those with positive antibodies the testicular size was normal in both sides. These findings agree with the theory of initiation of autoimmune process after a unilateral testicular damage, although we can not give data to support any damage to the contralateral testes.