The sperm characteristics of 38 male workers exposed to lead in a battery factory were studied. Sperm analysis was performed after 4 days of sexual abstinence. Parameters analyzed were: volume, sperm count, motility, and morphology. Exposure levels were estimated by measuring the concentration of lead and delta-aminolevulinic acid in the serum. Based on blood lead levels, the tested individuals were divided in three groups: A (12), B (11), and C (15). Significant levels of asthenospermia and teratospermia were found in exposed workers when compared with unexposed controls. Long-term exposure to lead may lead to changes in sperm characteristics and function.