Background: The aim of this study was to compare a conventional oncological inpatient rehabilitation programme with an inpatient step-by-step rehabilitation programme with regard to quality of life in breast cancer patients. Patients and Methods: Women with the diagnosis of breast cancer were randomly assigned to either the step-by-step programme (group A: 3-week rehabilitation plus 4 and 8 months later a 1-week sojourn each time) or the conventional rehabilitation programme (group B: 4-week stay and no further interventions afterwards). Quality of life was assessed with the QLQ-C30 of the EORTC at t(0) (beginning of the study), t(1) (end of 3- or 4-week stay) and t(2) (12 months after t(0), end of study). Results: Between t(0) and t(1), a tendency (0.1 > p >= 0.05) could be shown in group B towards better improvement in global quality of life and emotional function. In the subgroup of patients that had impaired functions of quality of life at t(0), superiority in group B reached significance (p < 0.05) for emotional and cognitive function at t(1). Between t(1) and t(2), cognitive function improved further in group A, but diminished in group B. For the subgroup of patients with impaired cognitive function at t(0), this difference between both groups became significant (p = 0.0098). Conclusions: Although not generally superior to conventional inpatient rehabilitation programmes, the analysed step-by-step rehabilitation provided marked benefits for patients with cognitive impairments.