Since the inception of adjuvant chemotherapy for osteogenic sarcoma (OS), 25 patients were treated for telangiectatic osteogenic sarcoma (TOS) from 1973 through 1980. This represented 12% of all patients with primary OS of an extremity seen during this time period. Tumors that demonstrated only focal areas of TOS with areas of other subtypes were designated not as TOS but as "mixed" subtypes of OS. In the 25 patients with pure TOS, surgery included 18 amputations and seven resections for the primary tumor. Ten patients were treated on the first chemotherapy protocol (T-4) including high-dose methotrexate (HDMTX) with citrovorum factor rescue (CFR), Adriamycin (ADR), and cyclophosphamide (CYC). Of those 10 patients, five have been free of disease for seven to ten years from the time of diagnosis. Nine patients were treated on the second protocol (T-7) including HDMTX with CFR, ADR, and the combination bleomycin, cyclophosphamide, and dactinomycin (BCD). Six of those nine patients are disease-free survivors 63 to 88 months (median, 63 months) from diagnosis. Six were treated on the third chemotherapy protocol (T-10) including HDMTX with CFR, ADR, BCD, and the substitution of cisplatinum for those not having a complete response to preoperative chemotherapy with HDMTX. All six of the latter are disease-free survivors 42 to 56 months (median, 49 months) from the start of treatment. Toxicity included two HDMTX-related drug deaths in patients started on treatment prior to 1977. Of the entire group, 17/25 (68%) have remained free of disease at a mean follow-up time of over five and one-half years. This study demonstrates that TOS is responsive to chemotherapy and is potentially curable. Some prior reports of the uniformly poor prognosis of this variant of OS should not discourage attempts of curative therapy by chemotherapy and surgery.