The association between infertility and a number of occupations and occupational exposures was examined in a case-control study utilizing data collected from medical records and mailed questionnaires. The results suggest that male exposure to heat and female exposure to noise, textile dyes and lead, mercury, and cadmium are associated with infertility. Further research is needed to examine the entire spectrum of abnormal reproductive and developmental outcomes of exposure to these agents and to identify their full effects.