OBJECTIVE This study investigated ideas and attitudes of breast cancer patients in two countries with reference to information on diet and their need for dietary counselling. METHODS Australian breast cancer (ABC) patients (n=215) surveyed for alterations in dietary habits after diagnosis were compared with breast cancer patients in Finland (FBC; n=139). A validated questionnaire was used. Logistic regression models were used to adjust for differences in demographic patient characteristics between the groups. RESULTS Eight per cent of FBC and 54% of ABC patients saw diet as a factor contributing to their disease (P<0.00001). Thirty per cent of FBC and 39% of ABC reported changing their diet after being informed of the diagnosis (P=0.033). Higher education, younger age and longer (>1 year) time to diagnosis were significantly associated with the probability of changing diet among the Australian patients. The main reason given was the desire for cure. The most common source of information was the mass media, and a need for more information on dietary factors relating to disease was expressed by 32% of patients in each group. CONCLUSIONS Ideas about the importance of diet varied significantly among ABS and FBC patients. The lack of precise dietary recommendations for the individual situation was commonly mentioned, and patients depended on information obtained from outside their treatment centre.