Aim/Background: Short hydration (SH) in chemotherapy containing cisplatin (CDDP) has become widespread in recent years. However, few large studies have reported the superiority of this method, compared with conventional hydration (CH), in terms of nephrotoxicities. Methods: We conducted a consecutive retrospective analysis of 467 patients with thoracic malignancies who had been treated with chemotherapy including CDDP between December 2009 and December 2013 at the National Cancer Center Hospital. All the cases had received aprepitant, 5-HT3 blocker and dexamethasone based on the antiemetic guidelines. Statistical analyses were performed to understand the risk factors for renal impairment after the administration of CDDP. The factors included in the analyses were as follows; age, sex, ECOG performance status (PS), concomitant thoracic radiotherapy, the dose of CDDP, degree of gastrointestinal adverse events, Mg supplementation, baseline creatinine (Cr) values, and method of hydration. Results: The patients' characteristics were as follows: male/female, 323/145 patients; median age (range), 62 (27-69) years; PS 0/1/2/3, 238/217/10/2 patients; and SH/CH, 111/356 patients. CDDP was administered with vinorelbine, pemetrexed, irinotecan, etoposide, docetaxel, gemcitabine or amurubicin (175, 148, 62, 34, 33, 13, and 2 cases, respectively). The percentage of patients requiring a dose reduction of CDDP in the SH group was 6.3%, while that in the CH group was 12.9%. The proportion of CDDP discontinuation because of nephrotoxicities was 0.9% in the SH group and 2.2% in the CH group. After CDDP-based chemotherapy, a Cr increase of more than Grade1 was found in 14.4% and 33.1% of the patients in the SH and CH groups, respectively, and the median estimated GFR values (mL/min/1.73m2) were 73.7 and 65.3, respectively. A logistic regression analysis revealed a significantly lower incidence of Grade 1 or higher Cr toxicity after the first cycle of CDDP based chemotherapy in the SH group(OR, 0.19; 95% confidence interval, 0.06-0.61; P = 0.006). Conclusions: Short hydration resulted in a significantly lower incidence of nephrotoxicity in CDDP-containing regimens. Disclosure: Y. Goto: membership on an advisory board or board of directors Lilly, Boehringer Ingelheim, Taiho. Y. Ohe: membership on an advisory board or board of directors Chugai, AstraZeneca, Lilly, Boehringer Ingelheim, Novartis, ONO, BMS. All other authors have declared no conflicts of interest.