Workers interested in tuberculous infection in children are aware that its incidence, measured either by clinical signs or by the presence of a positive reaction to tuberculin, has been decreasing. It has been my impression that this decline has been felt in Rochester and that the severity of the infection itself has been decreasing. This analysis was undertaken to determine the annual incidence of tuberculous infection here and the annual percentage of children with positive reactions to tuberculin who show clinical or roentgenologic evidence of the disease. Any change may in a manner determine whether the virulence of the organism has altered. GENERAL CONSIDERATIONS