The use of resources for breast cancer during the first five years after diagnosis by different stages of disease was evaluated on the basis of all breast cancer patients (555) diagnosed in the Tampere University hospital district (Finland). All outpatient visits or inpatient-days of these patients in any hospital of the district were recorded and the average costs of hospital-day and of outpatient visit were applied to quantify the total use of resources. During the first five years of follow-up 535 breast cancer patients had 8206 follow-up visits and spent 18472 days in hospital. The stage II-IV patients had more than twice as many outpatient visits and inpatient-days as the stage I patients. The number of hospital-days/patient-year was 2.4-fold for stage II patients and 4.1-fold for stage III-IV patients as compared to stage I patients. The overall use of resources/patient for those with nonlocalized disease was twice as high as the use for stage I patients, while the use of resources/person-year was 2.3-fold for stage II patients and 3.6-fold for stage III-IV as compared to stage I patients. Our study in an unselected patient population during the first five years of follow-up shows that breast cancer patients diagnosed in the early stage (stage I) require far fewer health care resources than if diagnosed in advanced stages. The results can be directly transformed into costs of breast cancer control by stage of breast cancer.