The study investigated the effects of betaine and ascorbic acid supplementation on serum gonadotropin, testicular histological features and sperm quality in male Japanese quails reared during the dry season. Two hundred and forty 14 day-old male Japanese quails, obtained commercially and housed in cages, were assigned randomly to four dietary treatments for 56 days. Each treatment comprised of 3 replicates (20 birds per replicate). Birds in Control group were fed only basal diet, while those in AA group consumed supplemental ascorbic acid at (200 mg/kg); BET group, betaine (2 g/kg) and AA + BET, a combination of AA (200 mg/kg) and betaine (2 g/kg) in diets. Feeds and water were offered to all birds ad libitum. The prevailing environmental conditions during the study predominantly exceeded the zone of thermal comfort for Japanese quails with DBT ranging from 25.0 to 37.0 °C; RH, 48.0-92.0% and THI, 69.8-91.0. At 28, 49 and 70 day-old, serum concentrations of malondialdhyde (MDA), superoxide dismutase (SOD), gonadotropins [luteinizing hormone (LH) and follicle stimulating hormones (FSH)] and testicular histological analyses were evaluated. Sperm quality was assessed in 70 day - old quails as sperm motility (SM), vitality (SV), total abnormalities (STA) and reserve (SR). Supplemental AA + BET decreased (P < 0.05) MDA, but improved (P < 0.05) SOD in 28, 49 and 70 day-old quails. Serum LH and FSH activities were enhanced (P < 0.05) in birds fed AA ± BET diets, but those which consumed BET or AA + BET showed enhanced (P < 0.05) testicular histological architecture and spermatogenic activities. Birds fed AA ± BET showed improved SM, SV and SR (P < 0.05), but lower STA in 70 days old male quails. It is concluded that supplementation of betaine and ascorbic acid enhances male reproductive potentials in Japanese quails during the dry season.