Tuberculosis continues to be an important health problem. A tuberculosis prevention and control program was begun in 1989 in Ciutat Badia, introducing the inclusion of those who had been in close contact with infected subjects. In the two years of the study, a total of 1,548 tuberculin tests was performed, 518 of which were positive 33%). Prevalence of tubercular infection in the study population, was 13.95%. Ages ranged from 14 to 20 years. We detected 20 cases of pulmonary tuberculosis and were able to study 91% of those who had been in close contact with the subjects in question. Three of these were detected in the latter study, and two by contact with tubercular infection. We prescribed a total of 180 chemoprophylaxes (47 primary and 133 secondary) with compliance of 60% and 71% respectively. We believe that chemoprophylaxis plays an important role in the prevention and control of tuberculosis in primary care.