Two patients with osteogenic sarcoma of the proximal tibia were treated pre-operatively with intensive chemotherapy with high dose methotrexate (HDMTX) with citrovorum factor rescue (CFR) and adriamycin (ADR). One patient died before surgery. The other underwent en bloc resection of the primary tumor with prosthetic replacement of the involved tibia, followed by adjuvant chemotherapy consisting of HDMTX with CFR and ADR, but died of metastases. Complete control of the primary or metastatic tumor was not achieved. It is emphasised that intensive multiple drug chemotherapy should be administered with extreme caution. The histologic findings are carefully analysed in relation to objective tumor response and toxic chemotherapy effects.