Since the late 1980s, polychemotherapy protocols for the treatment of childhood acute lymphoblastic leukaemia (ALL) derived from Western European and American regimens have been introduced in Russian paediatric oncology centres. Whereas treatment results were significantly improved compared with the results of former non-standard treatment strategies, the substantial toxicity of these protocols required a high standard of supportive care, and the high costs of treatment became a major problem. In 1991, a new protocol was developed with the aim of reducing toxicity and costs without affecting efficacy of the treatment. Since 1991, a single-centre study comparing the new Russian Protocol, Moscow-Berlin 91 (MB), with a modified version of the protocol ALL BFM 90 (BFM) of the Berlin-Frankfurt-Münster group was performed in Moscow to evaluate possible advantages of the new protocol under Russian conditions. The aim of the present analysis was to compare toxicity, need of supportive care and expense of both regimens (BFM, 25 pts; MB, 32 pts). Hepatotoxicity (liver enzymes), nephrotoxicity (creatinine), duration of neutropenia, and platelet transfusions were similar in both protocols. The median erythrocyte transfusion level was greater in the BFM (1000 ml/m2) than the MB patients (505 ml/m2, P < 0.01), as was the length of intravenous (i.v.) antibiotic therapy (22 days BFM versus 9 days MB, P < 0.01), treatment delays (39 days BFM versus 21 days MB, P < 0.001), and duration of in-patient treatment (47 days BFM versus 18 days MB, P < 0.001). Side-effects of the MB protocol occurred mainly during induction therapy. Total costs (mean cost/person/m2 body surface) of treatment including supportive care were 1.73-fold higher for the BFM protocol than MB, whereas costs of cytostatic drugs were comparable in both groups. In Russia both protocols were feasible. During consolidation therapy tolerance to treatment was better in MB 91 compared with BFM 90m, whereas toxicity during induction therapy was similar in both protocols. With respect to costs and side-effects, the MB 91 protocol appears to be an alternative to established protocols for countries with limited financial and clinical resources.