In the context of a medicoeconomic study of the adjuvant treatment of breast cancer, we evaluated the cost of the recurrence. This cost was assessed from the medical records of 146 patients having presented either distant metastases, or a local recurrence followed or not by metastases between 1983 and 1990. We checked according to published data that the frequency of the metastatic risk is negligible if beyond 5 years after the local recurrence. Costs are expressed in 1995 French Francs (FF), with the French Social Security point of view. From the medical records, we calculated the mean cost of each type of recurrence using medical costs (visits, drugs and treatments, assessments, tests, hospital care, outpatient services.) and non medical costs (patient transportation). The costs are 175,168 FF (standard deviation or SD: 127,972) for metastatic recurrence, and respectively 287,582 FF (SD: 142,280) and 115,705 FF (SD: 78,677) for local recurrence followed or not by metastases. There is a significant difference between these figures (p < 0.001). The hospitalization costs are around 66% of the total cost of each type of recurrences and they are significantly higher (p < 0.005) when metastatic disease occurs after a local recurrence. The mean cost of isolated local recurrence added to metastatic recurrence, 290,873 FF, is not different from that of local recurrence followed by metastases, 287,582 FF (p = 0.15). These results will be integrated in a model in order to evaluate the long-term economic consequences of an adjuvant strategy in the treatment of breast cancer and presented in other publications.