Background: Annona muricata has been widely used by majority of people in the treatment of diabetes, pain, fever, cancer and many others diseases. Despite these medicinal values of this plant, it is important to study its effect on semen factors that determines reproductive health. Materials and method: Sixteen male rats weighing 150-200g were given Annona muricata methanolic bark extract (AMMBE) for fourteen days at the dose rate of 0 mg kg^-1, 200 mgkg^-1, 400 mgkg^-1 and 800 mgkg^-1 representing groups A, B, C and D respectively. The sperm cells were analyzed to determine the sperm counts, morphological appearances and survivability. Testes were also fixed in formalin for histopathology. The results obtained were analyzed using standard statistical package. Results: The results showed that the sperm liveability of rats treated with Annona muricata methanolic bark extract (AMMBE) were statistically significantly lower in groups B, C and D having mean values of 78.50±1.62, 86.50±3.11 and 68.00±1.96 respectively while the control group had 91.00±2.86, sperm motility was found to be highest in control group with 93.50±3.22 while other groups (B, C and D) had 82.25±2.20, 87.50±1.96 and 71.25±2.34 respectively. This finding showed strong correlation between the sperm motility and live-death ratio. In addition, there was reduction in the sperm concentration in a dose dependent manner, while the testicular histology revealed lesions that indicate potential for structural damages. Conclusion: It was concluded that due to the reductions in sperm motility, sperm concentration and live-death ratio, Annona muricata prolonged use may be detrimental.