The OVIS study is a population-based study that aims at evaluating medical care in Schleswig-Holstein (Germany). In this paper, the health related quality of life (QoL, EORTC QLQ-C30 and -BR23) of 1,927 women with breast cancer is reported. The global health status/QoL score was comparable to reference data of the age-adjusted German general population, but clinical meaningful differences (> or = 10 points) were found for all functioning scales (with the exception of physical functioning) and for three of the symptom scales/items (fatigue, dyspnoe, insomnia) with OVIS patients showing more deficits. Furthermore, OVIS patients scored higher on the item financial difficulties. Logistic regression analyses revealed that coming from an urban surrounding, having a higher social status and attendance to a regular aftercare predicted a good overall QoL, while factors that were related to perceived complications in the course of the therapy raised the risk for a low QoL rating. It is of interest, that attendance to a rehabilitation and interest in self-help groups independently predicted an increased risk for a low quality of life. Overall, we assume the global QoL is rating slightly too optimistic since major deficits were reported on the specific physical and functional scales/items.