Nephroblastoma (Wilms' tumor) is frequently associated with mortality in children. MicroRNAs (miRNAs) are important for tumor development serving as oncogenes or tumor suppressors. In the present study, miRNA‑590 (miR‑590) was identified to be upregulated in Wilms' tumor tissues compared with the normal adjacent tissues. Additionally, the levels of miR‑590 were consistent with their clinical stage. Wilms' tumor 1 (WT1) was considered to be a tumor suppressor in certain tumor types, and it has been detected at low expression levels in various types of cancer with high cell proliferation and aggressive behavior. The expression levels of miR‑590 were quantified using reverse transcription‑quantitative polymerase chain reaction. Cell proliferation was measured using 5‑ethynyl‑20‑deoxyuridine assays. The protein expression levels of WT1 were investigated by western blot analysis. To the best of our knowledge, the present study was the first to determine that WT1 was a target gene of miR‑590 as miR‑590 was able to negatively regulate WT1 expression level by binding to the specific target site within the 3'‑untranslated region (3'‑UTR) of WT1 in G401 cells. Additionally, overexpression of miR‑590 promoted G401 cell proliferation which was consistent with the effect of small interfering RNA‑WT1. Subsequently, the present study determined that the cell phenotype altered by miR‑590 overexpression may be reversed by upregulation of WT1 in G401 cells. In conclusion, the observations indicated that miR‑590 may function as an oncogene via targeting WT1 to induce G401 cell proliferation. These results may contribute to current understanding of the function of miR‑590 in nephroblastoma.