This study aimed to determine the effect of Moringa (Moringa oleifera Lam.) leaf extract on the viability and motility of spermatozoa of rats (Rattus norvegicus) exposed to heat (40 ºC). A total of 25 rats aged 2.5 months and weighed 200 grams were randomly divided into five groups. Rats in K (–) group were not exposed to heat and without Moringa leaf extract administration. Rats in K (+) group were exposed to heat (40 ºC) for 1 hour daily without Moringa leaf extract administration. Meanwhile, rats in P1, P2, and P3 groups were administrated with Moringa leaf extract 100, 200, and 400 mg/kg BW/day, then exposed to 40 ºC 1 hour daily for 14 days. The results showed that exposure to 40 °C one hour per day for 14 days in K (+) group caused a decrease (p <0.05) on viability and motility of rat spermatozoa compared to those of the K (–) group. The administration of Moringa leaf extract (P1, P2, and P3 groups) was followed by an increase (p <0.05) in viability and motility of rat spermatozoa compared to the K (+) group. Viability and motility of rat spermatozoa in the P3 group (given Moringa leaf extract 400 mg/kg BW/day and exposed to 40 ºC 1 hour daily for 14 days) were not significantly different (p >0.05) compared to the viability and motility of rat spermatozoa in K (–) group. It could be concluded that administration of Moringa leaf extract 400 mg/kg BW/day can maintain the viability and motility of spermatozoa in white rats exposed to heat.