Nedaplatin(NDP)is a platinum derivative anticancer drug.An NDP dose of 100mg/m2 every 4 weeks is recommended in non-elderly Japanese patient because a higher dose may lead to myelosuppression, such as thrombocytopenia.In a pharmacokinetic analysis, thrombocytopenia was significantly correlated with renal function.However, the correct dose in patients with impaired renal function remains unclear.To evaluate the usefulness of dose reduction in patients with renal dysfunction, we conducted a retrospective study.This study included Japanese solid cancer patients who received NDP monotherapy in Nagoya University Hospital between April 2011 and March 2014. Eighty three patients were evaluated and divided into 2 groups based on renal function: a creatinine clearance(Ccr; mL/min)≥60 group and a Ccr<60 group.The frequency of B Grade 3 thrombocytopenia and neutropenia was significantly higher in the Ccr<60 group than that in the Ccr≥60 group (3.4% vs 32.0%; p=0.001 and 6.8% vs 32.0%; p=0.005, respectively).In the Ccr<60 group, the frequency of BGrade 3 thrombocytopenia and neutropenia was lower in the reduced dose group than that in standard dose(100mg/m2)group (41.7% vs 23.1%; p=0.410 and 41.7% vs 23.1%; p=0.410, respectively).A multiple logistic regression analysis revealed that NDP dose and serum creatinine were risk factors for the incidence of BGrade 3 thrombocytopenia and neutropenia.These results suggest that NDP dose should be reduced to achieve safe drug treatment in patients with Ccr<60.