Biochemical and physiological tests were carried out on the skin surface of 20 patients with candidal intertrigo and 27 patients with tinea cruris. In all patients the test areas were free of efflorescences. The same tests were performed in 39 and 27 resectively healthy test persons of the same age and sex. The following striking findings came to light: 1. There was a significant decrease in the percentage amount of squalene in the skin surface lipids of the moniliasis group as compared with the control group. 2. There was a significant decrease in the reducing substances in the so called water solubles obtained with the phenol sulfuric acid method in the moniliasis group. The same results were obtained when only those moniliasis patients who were definitely not suffering from diabetes mellitus were taken into account. This is presumably a question of a reduction in the bound carbohydrates. 3. There were significantly more amino acids extractable from the skin surface of the tinea cruris patients than of the control persons. These results point to important predisposing factors for the susceptibility to candidal intertrigo and tinea cruris respectively.