OBJECTIVE: Abnormal expression of Survivin has been found in the majority of tumor tissues and it can directly inhibit the expression of Caspase-3. It is suggested that Survivin plays an important role in the development of tumors. This study aims to investigate the expression of Survivin and Caspase-3 mRNA in Wilms tumor. METHODS: Survivin and Caspase-3 mRNA were detected by RT-PCR in 48 specimens from Wilms tumor tissues and 24 from adjacent normal kidney tissues. RESULTS: Survivin mRNA was expressed in 72.9% of Wilms tumor tissue samples, while no Survivin mRNA expression was detected in adjacent normal kidney tissues. In contrast, Caspase-3 mRNA was expressed in only 8.3% of Wilms tumor tissues but 45.8% of adjacent normal kidney samples (P< 0.05). CONCLUSIONS: Increased expressions of Survivin mRNA and decreased expression of Caspase-3 mRNA were found in Wilms tumor, and may be related to the development of Wilms tumor.