This study investigated the effect of ketogenic diet on monosodium glutamate (MSG)-induced testicular dysfunction. Forty-six male rats (180 ± 40 g) were grouped into two groups (23 rats each); control group and MSG-induced group (4 mg/kg bw) for 28 days. At the 29th day, 5 rats from both group were sacrificed to establish testicular dysfunction. The remaining animals from the control group was further divided into three sub-groups and treated for 42 days; untreated group, ketogenic diet only and curcumin only as the standard drug (150 mg/kg bw). In the pre-treatment, the administration of MSG resulted in a significant (p < 0.05) decrease in the testis-body weight ratio, alkaline phosphatase (ALP), acetylcholine esterase (AChE), cholesterol, triglycerides (TG), nitric oxide (NO), glycogen, protein and antioxidant enzymes in the testis. In the post treatment, the MSG only group significantly reduced testicular cholesterol, catalase (CAT) and NO. In contrast, MSG + ketogenic diet group showed a significant increase in levels of rat testicular acid phosphatase (ACP), ALP, cholesterol, HMG-CoA, TG, malondialdehyde (MDA), reduced glutathione (GSH) and NO. The ketogenic diet showed a significant increase (p < 0.05) in the levels of NO, ALP, cholesterol, HMG CoA reductase and (TG). In addition, significant increases in levels of rat testicular ACP, ALP, HMG-CoA, (CAT), SOD and GSH were recorded for MSG + Curcumin group. Taken together, the findings support the prospects of ketogenic diet to enhance the testicular function in rats.