This study investigates the effects of Cucumis sativus (cucumber) leaf extract on hormonal levels, semen quality, and sperm cell morphology in male Wistar rats. Thirty rats were randomized into three groups: control, 400 mg/kg, and 800 mg/kg extract-treated groups, and administered for 28 days. Hormonal assays revealed significant dose-dependent reductions in follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels in treated groups (p < 0.05). Semen quality analysis showed a significant decline in semen color, consistency, pH, sperm motility, and live proportion, alongside increased abnormal sperm morphology and non-motile spermatozoa, especially in the 800 mg/kg group. Furthermore, differential sperm abnormalities, including head deformities, twisted tails, and bent mid-pieces, were significantly elevated in treated groups, indicating structural and functional damage to sperm cells. The results suggest that Cucumis sativus leaf extract, at higher doses, impairs male reproductive hormones, semen quality, and sperm morphology, potentially due to oxidative stress or phytochemical-induced toxicity. This aligns with prior studies on phytotoxic effects of plant extracts, where flavonoids, alkaloids, and other bioactive compounds were implicated in reproductive toxicity. However, the exact mechanism underlying these effects remains unclear and warrants further exploration. This study provides a foundation for understanding the reproductive toxicity of Cucumis sativus leaf extract, emphasizing the need for cautious use of herbal preparations containing this plant.