Torsion of the spermatic cord is a urological emergency that must be treated with acute surgery. Possible long-term effects of torsion on testicular function are controversial. This review aims to address the impact of testicular torsion (TT) on the endocrine- and exocrine-function of the testis, including possible negative effects of torsion on the function of the contralateral testis. Testis tissue survival after TT is dependent on the degree and duration of TT. TT has been demonstrated to cause long-term decrease in sperm motility and reduce overall sperm counts. Reduced semen quality might be caused by ischemic damage and reperfusion injury. In contrast, most studies find endocrine parameters to be unaffected after torsion, although few report minor alterations in levels of gonadotropins and testosterone. Contralateral damage after unilateral TT has been suggested by histological abnormalities in the contralateral testis after orchiectomy of the torsed testis. The evidence is, however, limited as most human studies are small case-series. Theories as to what causes contralateral damage mainly derive from animal studies making it difficult to interpret the results in a human context. Large long-term follow-up studies are needed to clearly uncover changes in testicular function after TT and to determine the clinical impact of such changes.