The gliding testis is a testicle located below the external ring, can be manipulated to the upper scrotum, but is prone to ascend to its original position. Histologic changes can be detected in these gonads by 7 years of age. We evaluated 427 consecutive prepubertal boys referred for cryptorchidism. One hundred and twenty-three had classical undescended, 71 ectopic, 55 retractile, and 178 (mean age 6 years 2 moths) gliding testes. The gliding testes were smaller than controlaterals in 24% of boys. All gliding testes were unilateral whereas bilaterality was 85% in the retractile group (p < 0.0001), 17.5% in the undescended (p < 0.001), and 10% in the ectopic group (p < 0.01). A history for one or more of the following: orchidopexy (3), hormonal treatment (5), late testicular descent (9), spermatic cord torsion (5), testicular pain (10), actual retractile testes (20) or actual gliding testis (58), was present in 93 (52.2%) of the fathers of the gliding group. Forty-seven (81%) paternal gliding testes were hypotrophic. Seventy-five boys with gliding testis underwent initial hormonal therapy with transient benefit, and 57 were operated on. Two anatomical findings are typical of the gliding testis: the absence of the gubernaculum and a processus vaginalis partially patent from the upper scrotum to the mid groin area. This feature explains the mobility of the gliding testis from the external ring to the upper scrotum. The absence of the gubernaculum may be responsible for a higher incidence of spermatic cord torsion in this population. The gliding testis is a distinct entity, representing the mildest degree of a true undescended testis. As hormonal treatment gives only transient results, orchidopexy should be considered before testicular damage occurs.