To investigate the prevalence and type of congenital inverted nipple, and realizing that the condition is a disease for which treatment is necessary, 1,625 unmarried women aged between 19 and 26 were physically examined and responded to questions about inverted nipple. Fifty-three of 1,625 subjects (3.26%) presented with this malformation, and it was found in 3.05% of the 3,250 nipples examined. In 46 of the 53 (86.79%), the condition was bilateral, and in 7 (13.21%), it was unilateral. In such cases, inversion was found on the right side in two subjects and on the left side in five. Of the total number of congenital inverted nipples, 96.23% were umbilicated and 3.77% were invaginated. Nine of the 53 subjects with inverted nipple considered that the condition should be corrected. Prior to counseling and possible surgery, the medical practitioner must carefully consider all available information, and the data contained in this report may thus be useful.