This retrospective cohort study examined disability among 3686 men and 75 women employed as chemists in 1959 and followed through 1977. Overall, the chemists experienced fewer absences of .gtoreq. 8 consecutive days than expected on the basis of the experience of other salaried employees of the chemical company. Among the men, fewer claims than expected were observed for absences due to benign and unspecified neoplasia, heart disease and peptic ulcer and to diseases of the urinary system, bones and joints and skin. Chemists had lower than expected incidence rates of 1st myocardial infarction (90 observed, 149.8 expected). The deficits may be attributable to exposure misclassification or to confounding by smoking or socioeconomic status. A slight excess was seen for absences due to mental disorders.