The alkylating agent ifosfamide, an analog of cyclophosphamide, has demonstrated significant activity in soft tissue sarcoma and testicular carcinoma. Understanding and control of the urinary toxicity of ifosfamide therapy has allowed greater use and inclusion of ifosfamide in combinations in the treatment of malignant diseases. While preliminary results with ifosfamide in a number of diseases are encouraging, final determination of its efficacy awaits further study. A comprehensive review of preclinical data and clinical trials with ifosfamide is presented.