The amount of breast tissue within the inframammary fold (IMF) is controversial. Preservation of the IMF during mastectomy facilitates breast reconstruction and led some surgeons to practice conservation of the IMF, contrary to traditional descriptions of total mastectomy. The aim of this study was to analyse the clinical significance of IMF tissue content. A total of 50 IMF specimens were studied from 42 patients who underwent mastectomy between January 2001 and December 2002. The amount of breast tissue within each IMF was evaluated. The median patient age was 46 (range 33-86) years. The median body mass index was 23.4 (18.1-38.3)kg/m(2). The median IMF volume resected was 2 (0.2-9.7)cm(3) which was 0.6 (0.1-2.0)% of the breast volume. Ten specimens (20%) contained breast tissue and one (2%) contained breast tissue and an inframammary lymph node. Three specimens (6%) containing fibrofatty tissue without breast parenchyma had intramammary lymph nodes within the IMF. One patient (2%) who had a mastectomy for invasive ductal carcinoma had IMF tissue containing a lymph node within the IMF with breast cancer metastasis. The presence of breast tissue or lymph nodes within the IMF was unrelated to patient age, body mass index, the amount of IMF tissue in relation to breast volume and absolute breast size. Our finding that breast tissue and intramammary lymph nodes are present in 28% of IMF specimens requires re-consideration of the safety of preserving the IMF at mastectomy. If IMF tissue is resected and the immediate breast reconstruction is performed, the superficial fascial system should be reconstructed after excision of the IMF tissue in order to recreate the inframammary crease.