To investigate the functional and morphologic role of Aquaporin 7 (AQP7) in testis and sperm.Experimental laboratory study.University and research institute units.AQP7 knockout mice (C57BL/6J background).None.Morphologic analysis of testis and epididymis, daily sperm production, sperm motility, in vitro fertilization.There was no difference in the morphology of the testes and epididymis between AQP7 knockout and wild-type mice. The AQP7 knockout male mice and wild-type male mice had similar numbers of offspring. Analysis of the daily sperm production and motility of AQP7 knockout mice did not show any abnormalities. Similarly, the rate of in vitro fertilization using sperm from AQP7 knockout mice was not different from wild-type mice.Male AQP7 knockout mice were not sterile, and their sperm did not show any morphologic and functional abnormalities.