This study of hospital employee tuberculin conversion rates was undertaken in a 516-bed urban general hospital to determine if employment in such a hospital placed employees at risk of infection with tuberculosis. Data collected on the tuberculin status of employees from 1971 through 1976 indicated that the five-year conversion rate for all employees in a hospital-wide testing program was 7.1 per cent. Employees at greatest risk for conversion were nonWhite, age 46 through 64, in the lowest socioeconomic