Renal failure induced by cyclosporin A(CyA) in hematopoietic stem cell transplantation recipients is frequently observed as a major side effect. However, it is difficult to compare the frequency or severity among the reports because of differences in the method of administering CyA. In addition, there is little analysis of risk factors influencing the development of renal failure. Therefore, in this study, we tried to analyze risk factors influencing the development of renal failure induced by CyA in hematopoietic stem cell transplantation recipients at Chiba University Hospital using patient records. Among 50 patients in our study, 26 (52%) developed renal failure (grade 2 <), and serum creatinine reached maximum 32.7 days after the initiation of CyA administration on average. The mean blood CyA concentration was not correlated with the variance of serum creatinine (r = 0.12). In univariate analysis, the frequency of renal failure was significantly higher in females than that in males (<i>P</i> = 0.02). In addition, female and myeloablative conditioning were shown to be significant risk factors by multivariate analysis. These findings suggest that it is necessary to observe changes in clinical examination data such as BUN, uric acid, and serum creatinine more carefully because the risk of renal failure increases in patients with such risk factors.