In late 1992, three cases of tuberculosis were identified in school children attending a small elementary school in Sanremo, Italy. In order to identify further cases and determine the source, an epidemiologic investigation was undertaken. Tine test and X rays were performed on all students and school personnel. A total of 80% of the 59 students in the school had positive tine test reactions, as did 100% of the 12 teachers. All but one of the positive students had converted since last tested, as had the nine teachers who had been previously negative. The source of the outbreak was a teacher who had been in direct classroom contact with two of the five classes and had worked closely with the rest in building of a Christmas creche for the school. This outbreak suggests that increasing attention should be paid to school as potential foci for the spread of tuberculosis and that greater attention be paid to teacher screening, particularly in areas of higher tuberculosis prevalence.