Fifty-seven patients with advanced malignant tumours were treated with ifosfamide (Holoxan) and mesna (Uromitexan) in our department from November 1979 to December 1984. This series comprised eight cases of soft tissue sarcoma, nine cases of ovarian carcinoma, five cases of non-seminomatous testicular tumour, 11 cases of bronchogenic carcinoma, three cases of renal carcinoma, seven cases of non-Hodgkin's lymphoma, two cases of skeletal fibrosarcoma, two cases of breast carcinoma, one case each of Ewing's tumour, prostatic carcinoma, seminoma, plasma cell tumour, multiple myeloma, malignant teratoma, nasopharyngeal carcinoma, Wilms's tumour, neuroblastoma and mycosis fungoides. Out of these 57 cases, 53 were evaluable. There were five complete remissions and 20 partial remissions, corresponding to a total response rate of 47%. The overall median survival time (MST) of the 53 evaluable patients was 7.5 months. The responders had a longer survival time (MST 10 months) than the non-responders (MST 4.75 months) (p greater than 0.05). Analysis of the results according to sex, age, dosage of ifosfamide and degree of histological differentiation of the tumour cells failed to show any influence of these factors on the therapeutic results. The response rate to ifosfamide found in this study might be related to the histological origin of the tumours and to whether the primary tumours had been resected. The non-seminomatous testicular tumours, non-Hodgkin's lymphomas and ovarian carcinomas showed a high response rate. The response rate was higher in the group in which the primary tumour had been resected (61%) than in the non-resected group (12%) (except the non-Hodgkin's lymphoma). The side-effects of this regimen were moderate. Dyspepsia, nausea, vomiting, myelodepression, dizziness, and alopecia were common. Cystitis could be prevented nearly completely by concomitant administration of mesna, when given correctly, for preventing side-effects of ifosfamide on the urinary system (haemorrhagic cystitis, etc.).