A nationwide questionnaire survey was carried out on low-dose cisplatin-5-FU therapy for solid malignant tumors (mostly stomach and colon cancer) regarding its antitumor as well as adverse effects. The regimen was defined as 4 weeks administration of cisplatin 2-5 mg/body, 5 days a week, which was used in 47% of 82 institutions studied. Cases were classified into an Ab regimen (86 cases) with cisplatin 3-5 mg/body, and a Bb regimen (122 cases) with cisplatin 6-30 mg (mostly 10 mg)/body, both of which were given 5-FU 300-500 mg/body daily. The antitumor effect (CR + PR) was shown to be slightly higher in the Bb regimen than in the Ab regimen, and was 35% overall. Very few adverse effects appeared with either regimen for mostly major digestive, hepatic and renal functions, except for myelodepressions (leucopenia and thrombocytopenia), which were more than grade 3 in only a few percent with the Ab regimen, and a little more than 10% with the Bb regimen. The advantages and disadvantages of the A/Bb regimens appeared to be counter-balanced in terms of their antitumor and adverse effects. Most institutions using the Ab regimen favored repeating the regimen cycle as much as possible. Those using more than 6 cycles accounted for about 20% of hospitals.