摘要:INTRODUCTION: Organophosphate compounds (OPCs) are suspected to make changes in reproductive function by oxidant/antioxidant balance disruption in the brain, consequently impairing hypothalamic, pituitary endocrine functions, and gonadal processes. The aim of this study was to investigate the effects of occupational exposure to OPCs on the reproductive system of farm workers, in Hamadan, Iran. MATERIALS AND METHODS: A comparative study was conducted in rural farmers and urban men aged 20–40 years. After sampling and analysis of semen quality parameters (such as sperm count, sperm motility, progressive sperm motility, and sperm morphology), serum butyrylcholinesterase (BChE) activity (a specific biomarker in OPCs exposure), as well as total antioxidant capacity, nitric oxide, and lipid peroxidation levels for both semen and serum samples were determined. In addition, serum samples were analyzed for reproductive hormones, including follicle-stimulating hormone, luteinizing hormone (LH), and testosterone. RESULTS: Our findings showed that the number of sperms ( P = 0.04), their motility ( P < 0.001), and progressive status ( P < 0.001) in rural farmers were significantly lower than the urban population. In addition, a significant decrease was observed in BChE activity ( P < 0.001) and LH level ( P < 0.001), and also a remarkable increase was found in testosterone level ( P = 0.0014) in the serum of rural farmers compared to the urban population. Along with a decrease in semen total antioxidant capacity, a positive significant correlation was found between sperm motility and semen antioxidant capacity ( r = 0.45; P < 0.05). CONCLUSION: Exposure to OPCs may affect reproductive outcomes through impairing hypothalamic and/or pituitary endocrine dysfunctions and gonadal processes in farmers.