Zinc finger protein 185 (ZNF185) belongs to the ZNF family and is involved in cell proliferation and differentiation. To the best of our knowledge, the association between ZNF185 and male reproduction is unknown. In the present study, the expression and localization of ZNF185 in mouse testis, as well as its role in testosterone secretion, cell cycle progression and apoptosis of mouse Leydig cells were investigated. The results of the immunofluorescence analysis indicated that ZNF185 was highly expressed in Leydig cells of the mouse testis, and primarily localized in the cytoplasm. The results of quantitative polymerase chain reaction and western blot analyses further validated that ZNF185 expression was significantly higher in Leydig cells and sperm compared with that in Sertoli cells. Subsequently, the expression pattern of ZNF185 in mouse testis was determined at different developmental stages. The results demonstrated that the expression of ZNF185 was highest in the testis of 10‑week‑old mice and lowest in 2‑week‑old mice. Furthermore, the role of ZNF185 in Leydig cells of the mouse testis was investigated. Different concentrations of luteinizing hormone (LH) were used to stimulate the Leydig cells and subsequently the expression of ZNF185, and testosterone concentration was detected. The results revealed that LH upregulated the expression of ZNF185 and testosterone secretion, and ZNF185 expression was significantly positively correlated with testosterone secretion. To further validate whether ZNF185 was involved in testosterone secretion, lentiviral‑mediated RNA interference was used to knock down ZNF185 expression in Leydig cells. The results demonstrated that ZNF185 expression and testosterone secretion of Leydig cells were decreased significantly. In addition, the results demonstrated that the knockdown of ZNF185 expression did not significantly affect cell cycle progression or apoptosis. Taken together, the results of the present study revealed that ZNF185 was highly expressed in Leydig cells of the testis and involved in the secretion of testosterone. These results have contributed to the elucidation of the mechanism underlying male reproduction and may provide a novel target for the treatment of infertility, and the development of a contraceptive vaccine.