Cisplatin therapy induces kidney injury as a side effect. Thus, replacement fluid must be administered to prevent kidney injury. In our hospital, we use a Gemcitabine and Cisplatin combination chemotherapy (GC) at a total volume of approximately 500 mL for biliary tract cancer. We investigated the safety of GC with a small amount of replacement fluid. As a result, no serious adverse events and renal injury occurred that required discontinuation of treatment. The median overall survival time was 260 d (95% confidence interval, 154-367 d). This study suggests that GC with a small amount of replacement fluid could be performed tolerability. But we need to be careful about choosing patients such as patients who can drink 1 L orally and patients who can be treated as outpatients.