A serious Public Health problem in Rio de Janeiro State, tetanus in this State of Brazil presents an average morbidity coeficient of 9,6/100.000 inhabitants. The morbidity is different among the municipalities of the State, being greater in the municipalities of the litoral, in zones of low altitude. Based on studies of soil contamination by C. tetani made by foreing authors and in a preliminary report, the authors colleted 608 soil samples from 60 municipalities of Rio de Janeiro State, during the spring, and made cultures and biological tests to investigate the presence of C. tetani. Bacillus was found in 167 samples (27,4%) collected in pastures, streets, beachs, gardens, etc. C. tetani was unequaly distributed through the State, being more frequent in zones of low altitude, but was found also in zones of temperated climate of the mountains. A statistical analysis demonstrates the relationship between the morbidity of tetanus and the contamination of soil by C. tetani in this State, but the relationship was not absolute in ali municipalities.