This study examined the relationship between demographic features and aetiological causes of male infertility. Primary infertility was the presentation in 78% of patients. The incidence of varicocele was the highest (31%), whereas only 4.6% had vasectomy reversal and 7.4% of men were diagnosed with idiopathic infertility. Using the chi-squared test, there was no significant difference in the incidence of different causes of infertility among different ethnic groups (White, African-American, Asian, Hispanic, and other). Furthermore, there was no increased incidence of infertility aetiology with any particular occupation, race, religion, smoking or alcohol intake. In this study population, there was no association between the various risk factors (occupation, smoking, alcohol intake, and race) and the aetiologies of infertility. The proportion of patients diagnosed with idiopathic infertility was significantly less than reported in the literature.