OBJECTIVES: According to the existing guidelines FAC and CMF protocols for the treatment of early breast cancer are equaly effective. The objective was to evaluate safety profile and pharmacoeconomic aspects of these two protocols, the study was performed at Internal Oncology Clinic, Oncology Institute of Vojvodina. METHODS: Two treatment protocols were used: CMF (cyclophosphamide 600mg/m2, methotrexate 40mg/m2, fluorouracil 600mg/m2) in 19 women or FAC (fluorouracil 500mg/m2, doxorubicin 50mg/m2, cyclophosphamide 500mg/m2) in 42 women. Alltogether 61 women were included into study. Frequency and gradus of unwanted effects were measured during five days after one arrival for the treatment. Neuthropenia was measured by counting white blood cells 18-20 days after chemotherapy. Diarrhoea, nausea and vomiting were graduated by counting of number of episodes per day for five days after each treatment. For each protocol the costs of treatment for cytostatics as well as for treatment of unwanted effects and need for prolonged hospitalisation were calculated. RESULTS: There was a higher incidence of nausea, vomiting and neuthropenia in FAC vs. CMF treatments (73.81%, 23.57%, 21.43% vs. 57.98%, 15.79%, 10.53%) and higher incidence of diarrhoea in CMF vs. FAC treatments (5.68% vs. 2.38%). Anthracycline-based protocols (FAC) caused greater severity of nausea, vomiting and diarrhoea than CMF with equaly severe neuthropenia. Drugs used for treatment of nausea, vomiting and neuthropenia were setrons, corticosteroids and metoclopramide. The cost for the one treatment episode for cytostatics were higher for FAC (66.94EU pre single dose, 401.64EU for the whole cycle) than for CMF (19,10EU per single dose, 229.20EU for whole cycle). The costs of drugs used for the treatment of AEs were 13.20EU/patient/episode reciving CMF and 17.24EU/patient/episode reciving FAC protocol. CONCLUSIONS: CMF is safer and cheaper than FAC protocol.