Nine cases of comproved acquired toxoplasmosis (lymphatic form), from a Seminary in Bragança Paulista, (Brazil) motivated a clinical and serological survey. According to the data, at least 30 people (in a total of 81) presented, then, toxoplasmosis. Three hundred fourteen (314) dye-tests and indirect immunofluorescent tests were performed in all. The serological survey based on dye-test antibodies was extended to some local animal species. In view of the epidemiological survey limitations and notwithstanding the fact that a number of hipothesis have been suggested, no conclusions have been drawn, as far as the epidemiological aspects of the epidemics are concerned. Reporting this occurrence for the first time in the medical literature, the authors point out to the possibility of these outbreaks in closed institutions and in the rural area. They insist on the need for more complete researches, in similar situations, for the recognition of the sources and transmission mechanisms of the infection. Research work must be carried out in spite of the difficulties inherent to this subject.