Background and Objective: Obesity has been found to be associated with testicular dysfunction, resulting in decreased sperm quality, testosterone production and consequently male infertility. The aim of this study was to determine the effects of limonin on sperm count and motility and serum testosterone level in obese rats. Methods: Male Sprague-Dawley rats were divided into the following groups; the control, the obesity (Obesity), the obesity treated with limonin at dose 100 mg/kg (LM 100) groups at the last four week of the experiment. At the end of experiment, body weight and retroperitoneal fat were measured. Sperm count and motility measurement was performed. Serum testosterone and testicular MDA level were investigated. Results: Obesity significantly elevated body weight and fat accumulation while decreased the caudal epididymal sperm concentrations and percentages of sperm motility and serum testosterone compared to the control groups. (p<0.05). Treatment with limonin significantly reduced body weight and fat mass (p<0.05). An improvement of sperm concentrations and percentages of sperm motility and serum testosterone was observed in LM 100 group (p<0.01). Testicular MDA significantly increased in Obesity, while limonin treatment significantly diminished testicular MDA level (p<0.01). Conclusion: Limonin treatment potentially represents as a supplementation for the prevention of testicular dysfunction induced by obesity.