Wilms tumour is the most common tumour of the pediatric kidney. Elevation of hypoxia‐inducible factor 1α (HIF‐1α) has been detected in 93% to 100% of human Wilms tumour specimens, suggesting a potential value of HIF‐1α as a therapeutic target for Wilms tumour. In the present study, a stable HIF‐1α‐silenced Wilms tumour cell strain was established by introducing HIF‐1α short‐hairpin RNA (shRNA) into SK‐NEP‐1 cells. Silencing of HIF‐1α significantly reduced single‐cell growth capacity, suppressed proliferation and arrested cell cycle of SK‐NEP‐1 cells. In addition, reduction of HIF‐1α expression induced apoptosis in SK‐NEP‐1 cells, which was accompanied by increased levels of cleaved caspase‐3, cleaved poly (ADP‐ribose) polymerase (PARP) and Bax as well as downregulation of Bcl‐2 in the cells. Furthermore, when inoculated subcutaneously in nude mice, HIF‐1α‐silenced SK‐NEP‐1 cells displayed retarded tumour growth and impaired tumour angiogenesis. In summary, the findings of this study suggest that HIF‐1α plays a critical role in the development of Wilms tumour, and it may serve as a candidate target of gene therapy for Wilms tumour.