Summary A histopathological study was undertaken on breast tissue dissected during the course of 207 consecutive forensic post-mortems on women over the age of 15 years in order to define the frequency and types of lesions found in Australian women. At least 10 blocks were obtained from each breast and a total of 4,738 blocks were examined. A particularly high frequency of atypical hyperplasia (12.6%), carcinoma in situ (13.0%), focal secretory change (24.1%) and perilobular haemangiomas (11.2%) was found. The radial scar, considered by some to be a precursor of infiltrating ductal carcinoma was found in 7.7% of the women.