Neonicotinoid insecticides usage is currently widespread, but this poses a challenge when considering the potential for occupational and environmental contamination. One of the most extensively used insecticides is thiamethoxam (TMX), a second-generation neonicotinoid insecticide. This study aimed to see if sub-lethal dosages of TMX insecticide had any negative impacts on epididymal sperm parameters, serum hormones, oxidative status, and testicular histology. The experimental cohorts were given a low dose of TMX (156 mg/kg bw), a high dose of TMX (312 mg/kg bw), or an untreated control for eight weeks. The sperm count, percent of viability, motility, and motility progressing and fructose level significantly decreased in both TMX-treated groups compared to the control group. Furthermore, TMX administration induced sperm morphological defects, serum hormone disturbances as significant reduction testosterone level, oxidant/antioxidant status imbalance as significant decline in catalase (CAT) and glutagthione peroxidase (GSH) content and significant rise in malondialdehyde (MDA) level and testicular histopathological alternation. TMX caused significant increase DNA damage in testicular tissue represented in tail DNA percent, comet percent, comet length, tail moment, and Olive moment. In conclusion, TMX exposure may have a deleterious impact on male albino rats' fertility through spermatogenesis, steroidogenesis and testicular redox status disruption, and testicles DNA impairment.