Patients who receive radiotherapy need to be informed about its effects. Available evidence is inadequate because it has focused on selected symptoms and has emphasized the objective characteristics of symptoms rather than the patients' own experience of them. This study therefore examined women's own accounts of physical side-effects during the first 12 months after treatment for early breast cancer. Semi-structured audiotaped interviews with 15 patients 1 week to 12 months after treatment were analysed qualitatively. The women described some symptoms that were consistent with what is already known, in particular fatigue and skin changes, but also others that have been previously neglected. The women's explanations for symptoms were an inextricable component of their experience of them. Surprisingly, many women blamed themselves for having caused their symptoms. These findings contribute to the evidence that is necessary to inform health care professionals' advice to patients. They can also guide future quantitative research into symptoms associated with treatment and ensure that this is grounded in patients' experience of symptoms rather than clinicians' assumptions about patients' experience.