T cell lymphoma is treated by administering to a patient suffering from T cell lymphoma a therapeutically effective amount of 10-propargyl-10-deazaaminopterin. Remission is observed in human patients, even with drug resistant T cell lymphoma at weekly dosages levels as low as 30 mg/m2. In general, the 10-propargyl-10-deazaaminopterin is administered in an amount of from 30 to 275 mg/m2 per dose.
