In a prospective study of lead neurotoxicity, exposed foundry workers and referents were evaluated using a comprehensive set of neurobehavioral tests. Other performance indexes were used including a questionnaire, physical examination, and nerve conduction testing. Results show increased rates of depression, confusion, anger, fatigue and tension among workers with blood levels over 40 mcg/dl. Other aspects of neurobehavioral function, including verbal concept formation, memory, and visual/motor performance were also impaired. In view of the large number of individuals exposed to lead in their work, specific inquiries should be made of individuals with affectual complaints to clarify the nature of their work and workplace exposure to lead.