The aim of this study was to determine the effect of the reduction of the length of hospital stay after surgery for breast cancer on the rate of care consumption and the cost of care. Patients with operable breast cancer were randomised to a short or long postoperative hospital stay. Data on care consumption were collected for a period of 4 months in diaries administered by patients, and socioeconomic status was evaluated by questionnaires. A cost minimisation analysis using the ‘societal’ perspective was performed and savings were compared with the savings of hospital charges. The use of professional home care was higher for the short stay group during the first month (7.2 versus 1.3 h, P<0.0001). The number of out-patient consultations, the intensity of informal home care and patient’s expenses did not increase after early discharge. The total cost of care was reduced by US$1320 by introducing the short stay programme (P=0.0007), but the savings were substantially lower than the savings in hospital charges (US$2680).