The study aimed to evaluate the effect of the addition of aloe vera raw extract on the capacitation of bovine spermatozoa during the in vitro fertilization process. Hyper activated motility (HAM) and acrosome reaction (AR) of sperm cells, as well as in vitro fertilization and cleavage rates are the main parameters used to estimate the aloe vera’s effect on bovine spermatozoa’s fertilizing ability. In the current study, two different concentrations of aloe vera (5 and 10 µg/ml) were used. Frozen thawed semen spermatozoa were subjected to a swim-up technique to separate the motile spermatozoa and capacitated in modified Sperm Tyrode’s albumin lactate pyruvate (S-TALP) medium supplemented with heparin only without aloe vera treatment (positive control), heparin+5µg/ml aloe vera, heparin+10µg/ml aloe vera, and finally the negative control tube, which was supplemented with 5µg/ml aloe vera without adding heparin. Sperm cells were incubated for 90 minutes at 39C0 in a 5% CO2 incubator and evaluated every 30 minutes at intervals. Cumulus oophorus complexes (COCs) were matured in a 5% CO2 incubator at 39C0 and inseminated in vitro with frozen-thawed bull sperm at the above concentrations. The inseminated oocytes were incubated at 39C0 in a 5% CO2 incubator for 24 hours and then examined for evidence of fertilization. The current study revealed that the aloe vera concentration of 10µg/ml at incubation time (60 minutes) had the best effect on sperm capacitation and acrosome reactions. The overall percentage of spermatozoa with progressive motility (PM) had declined across all groups as time progressed, with a significantly lower value found at the above concentration, as well as the effect of sperm treated with aloe vera on fertilization rate. The results showed that the proportion of fertilized oocytes was significantly increased at the aloe vera concentration of 10µg/ml compared to the other concentrations (5µg/ml), positive control, and negative control, respectively. In conclusion, treatment of bull spermatozoa with 10 µg of aloe vera extract/ml semen was considered the most efficient concentration for enhancement of sperm capacitation as a high IVF rate was obtained in Holstein Bull.