The 58-kDa microspherule protein (MSP58) has been reported to play an important role in the tumorigenesis and progression of cancers. However, little is known about the role of MSP58 in human renal cell carcinoma (RCC). In this study, we investigated the expression and biological roles of MSP58 in RCC. The results indicated that the expressions of MSP58 at both mRNA and protein levels were greatly up-regulated in human RCC tissues and cell lines. Down-regulation of MSP58 significantly suppressed the proliferation, migration/invasion of RCC cells, as well as attenuated tumor growth in a 786-O xenograft model in vivo. Mechanistically, knockdown of MSP58 expression sharply down-regulated the protein expression levels of β-catenin, c-myc and cyclin D1 in 786-O cells. Taken together, these findings showed that MSP58 downregulation suppressed the proliferation and invasion of RCC cells, at least in part, through regulating the Wnt/β-catenin signaling pathway. Thus, MSP58 may act as a novel therapeutic target for the treatment of RCC.