BackgroundMale infertility is a global problem, and varicoceles are a common and treatable cause of male infertility. This study prospectively evaluated the effects of varicoceles on the fertility status and potential among Nigerian men. The consequences of the presence, location, and grades of varicoceles on the fertility status of infertile men with varicoceles were determined using a Doppler scrotal ultrasound scan and their seminal fluid parameters.MethodsOne hundred infertile males with clinical varicoceles (study group) and 100 infertile males without varicocele (control group) were recruited. Varicoceles were confirmed/excluded and graded with an ultrasound scan in each subject. They also all had a seminal fluid analysis to measure their fertility potential. The findings were compared and correlated in the two groups.ResultsMost subjects in the study group (67%) had bilateral varicoceles, 31% had isolated left varicoceles, and only 2% had isolated right varicoceles. The majority of the participants (61%) in the study group had secondary infertility, while the majority (63%) in the control group had primary infertility (p = 0.001). There were significant increases in the prevalence of azoospermia (p = 0.008) and oligospermia (p = 0.030) with the higher grades of left varicoceles.ConclusionBilateral varicoceles were significantly present in males with infertility in the study group. Varicoceles were more common in males with secondary infertility, and higher grades of varicoceles were significantly more associated with azoospermia and severe oligospermia. We recommend the routine use of ultrasound scans to diagnose varicoceles for the optimal management of infertile male patients.