The controversies surrounding hormone replacement therapy have left many women confused and afraid. Providers have been faced with long-standing assumptions challenged by an abundance of new data in the past few years, with little guidance on how to interpret these findings. The objective of this paper is to provide a framework for understanding breast cancer risk associated with postmenopausal hormone replacement therapy, with a particular focus on how observational studies and randomised trials provide complementary information. This framework considers the data on risks of various hormonal preparations, the profiles of women at risk, and ends with an expert opinion in this context.