Preservation of the inframammary fold (IMF) at the time of mastectomy facilitates immediate breast reconstruction. Twenty-four IMF specimens were removed separately after mastectomy for cancer, were serially sectioned, and were examined histologically. Computer image analysis was used to calculate the percentage of breast tissue in each specimen. The mean volume of IMF tissue removed was 99 cm3 (27.3-205.2 cm3), and the mean area examined histologically was 3,036.3 mm2 (294-11,755 mm2). Breast tissue was identified in 13 of the 24 specimens. All cases were negative for carcinoma, but one case had a focus of ductal hyperplasia, usual type. The mean percent breast tissue in those positive for breast tissue was 0.04 percent and 0.02 percent overall. Preservation of the IMF leaves a minimal amount of breast tissue and does not appreciably effect the completeness of a mastectomy.