Several studies have demonstrated an elevated prevalence amongst professionals of mycobacterium tuberculosis, both in the rate of infections and illness. This study was carried out in a School Hospital in Campo Grande, MS, Brazil, aiming to establish the prevalence of infection with Mycobacterium tuberculosis. The results of the analysis of 194 subjects showed an overall positivity for the tuberculin test of 38.7%. There was a correlation with smoking (p=0.01, RP=1. 72 (1.20-2.45- Yates's correction). The conclusion is that the establishment of a program of tuberculin screening jointly with the implementation of interventions is necessary in order to reduce the risk of nosocomial transmission.