Data from couples (n = 103) seeking artificial insemination with donor sperm because of poor sperm quality and a control group of couples treated by in-vitro fertilization due to female causes were analysed according to the occupations of the spouses. Comparison of occupational categories revealed a significant difference in the prevalence of agricultural occupation (11/103 vs. 1/103, p < 0.01) between the group with male factor infertility and the normospermic controls. These patients also reported more long-term exposure to several insecticides and other pesticides. These toxic chemicals probably have a detrimental effect on male fertility and therefore we suggest more caution in the way they are handled.