Abstract: The survey was made on a large number of building workers.Among the 1736 persons investigated, 21% developed scrotal dermatitis abruptly. In the 282 patients, 27.6% were found to be accompanied by mycotic infections. Insufficient intake of riboflavin was the cause of the scrotal dermatitis, and poor hygiene was responsible for the infection of candida albicans. Observations were followed for two years, and it was proved that the measures of treatment and prevention adopted were effective.