A total of twenty healthy Egyptian buffalo bulls with an average of 500 kg live weight and 2.5 - 4.0 years old was used to study the effect of selenium and vitamin E (Se+Vit. E), Se and zinc (Se+Z), Vit. E+Z and Se, Vit. E+Z) on sexual desire, testicular measurements, some physical semen characteristics and liver function of buffalo bulls. The experimental animals were divided into five similar groups (4 bulls each). Bulls in the 1st group were left without any treatment and served as a control group (G1). Bulls were i.m. injected with 10 mg Se as sodium selenite and oral dose (100 IU) of Vit. E as α-tocopherol acetate per head (G2); i.m. injected with 10 mg Se and oral dose (5 g) of zinc oxide per head (G3); oral dose (100 IU) of Vit. E plus 5 g zinc oxide per head (G4); or i.m. injected with 10 mg Se and oral dose (100 IU) of Vit. E plus 5 g zinc oxide per head (G5). All treatments were twice/week for five months experimental period, two months as preliminary period and three as a main collection period. During the main collection period, sexual desire, testicular measurements, semen ejaculate volume (SEV), progressive sperm motility (PSM), sperm abnormality (SAB), sperm cell concentration (SCC) and total sperm output (TSO). Results showed that reaction time (RT) was shorter (P<0.05) and serum testosterone concentration was higher in all treated groups than in the control group. The shortest RT (68.92 sec) and the highest testosterone concentration (0.77 ng/ml) were recorded in G4. Values of testicular volume, scrotal circumference and testis tone firmer were higher (P<0.05) in all treated groups than in the control group, being the highest in G4 and the lowest in G1. Both SEV and percentage of PSM increased (P<0.05) in G2, G4 and G5 as compared to G1. The highest values of SEV and PSM were obtained for G4; however, values of G3 treated with Se+Z did not differ significantly from those in G1. Percentage of SAB reduced (P<0.05), while sperm cell concentration (SCC/ml) and total sperm output (TSO/ejaculate) increased (P<0.05) in all treated groups as compared to the control one. In conclusion, the current study may indicate beneficial effects of in vivo treatment of buffalo bulls with oral dose of Vit. E (100 IU) as α-tocopherol acetate plus 5 g zinc oxide per head twic/week for two preliminary months and three main semen collection months on sexual desire, testicular measurements and semen quality.