Background/aim: To study the effect of kisspeptin, a gonadotropin release stimulator, on the testicular tissue of the rat. Materials and methods: Four groups were formed as follows: control, Kiss-10 50 nmol administration for 1 day, Kiss-10 administration for 13 days, and one last group kept for 7 days following Kiss-10 applied for 13 days. Testicular tissues were stained with hematoxylin-eosin, periodic acid Schiff, Masson trichrome staining, terminal deoxynucleotidyl transferased UTP nick-end labeling, and Ki-67 immune staining. Serum testosterone levels were determined. Results: Serum testosterone level increased following acute application, while it was reduced by chronic treatment. Spermatogenic cells as stained by Ki-67 and TUNEL increased in the treated groups compared to the controls. Following a 7-day rest after treatment, a decrease in testosterone levels and Ki-67–stained cell numbers and an increase in TUNEL-stained cells were observed. Leydig cells showed increased vacuolization in the Kiss-1 group. Leydig cell vacuolization continued in the Kiss (13) group and was reduced in the Kiss (13 + 7) group. Conclusion: Kiss-10 increased spermatogenic cell proliferation, while testosterone level and proliferation decreased and apoptosis increased during the waiting period.