The chemotherapy side-effects are insufficiently documented while they strongly condition patients' quality of life. The aim of the study was to assess by means of a self-administered questionnaire the somatic symptoms experienced by breast cancer patients during their NCF (mitoxantrone + cyclophosphamide + 5-fluorouracil) chemotherapy and to demonstrate the interest of this self-report by comparing the frequency of side-effects assessed by the patients to that noted by the physicians in medical records. The study was carried out among 44 patients receiving their chemotherapy + radiotherapy at the Paoli-Calmettes Institute (marseille) between July 1994 and May 1995. The questionnaire comprized of 17 symptoms evaluated in terms of frequency, duration/severity and distress. The most frequent symptoms are: hair loss and nausea (75%), hot flush (57%), lack of appetite and headache (46%) associated with distress in 67 to 100% of cases. Their frequency was underestimated by the physicians in medical records. This study showed a large discordance patient-physician in the assessment of chemotherapy side-effects. The type of tool presented in this study could complement the usual scales of toxicity that do not provide an estimation of true patients' experience.