Abstract Objective In this study, we investigated to which extent patients feel well informed about their disease and treatment, which areas they wish more or less information and which variables are associated with a need for information about the disease, medical tests and treatment. Methods In a German multi-centre prospective study, we enrolled 759 female breast cancer patients at the time of cancer diagnosis (baseline). Data on information were captured at 5 years after diagnosis with the European Organisation for Research and Treatment of Cancer (EORTC) Information Module (EORTC QLQ-INFO24). Good information predictors were analysed using linear regression models. Results There were 456 patients who participated at the 5-year follow-up. They reported to feel well informed about medical tests (mean score 78.5) and the disease itself (69.3) but relatively poorly about other services (44.3) and about different places of care (31.3). The survivors expressed a need for more information concerning: side effects and long-term consequences of therapy, more information in general, information about aftercare, prognosis, complementary medicine, disease and therapy. Patients with higher incomes were better informed about medical tests (β 0.26, p 0.04) and worse informed with increasing levels of fear of treatment (β − 0.11, p 0.02). Information about treatment was reported to be worse by survivors > 70 years old (β -0.34, p 0.03) and by immigrants (β -0.11, p 0.02). Survivors who had received additional written information felt better informed about disease, medical tests, treatment and other services (β 0.19/0.19/0.20/0.25; each p < 0.01). Conclusion Health care providers have to reconsider how and what kind of information they provide. Providing written information, in addition to oral information, may improve meeting those information needs.