The global prevalence of diabetes mellitus is on rise. Diabetes is associated with changes in testicular tissue and thus affecting reproductive functions. Liraglutide is a glukagon-like peptide-1 receptor agonist and stimulates insülin secretion. The present study is the first to investigate the effect of liraglutide on testis histology and reproductive parameters in streptozotocin-induced diabetic rats. Twenty seven mature male Sprague-Dawley rats were randomly divided into three gropus, i.e, healthy control, diabetic control and liraglutide-treated diabetic rats. Diabetes was induced by two doses of streptozocin in a 3 day period (30 mg/kg; i.p). Treatment group was enjected with liraglutide (Novo Nordisk, Denmark) enjections (0.3mg/kg/12 h s.c) for 12 weeks. Animals were anesthetized by ketamine (60mg/kg/i.p) and xylazine (7.5mg/kg/i.p). Serum levels of total testosterone, LH and FSH were analysed by sandwich enzyme immunoasey method. Testicular tissues were dissected out of a whole via midline abdominal incision and underwent to histological analyses. Testicular damage, apoptosis and neovascularisation were also evaluated by VEGF and Bcl-2 using immunohistochemistry methods.