To seek out the potential microRNAs (miRNAs) that target Wilms' tumor suppressor 1 (WT1), a transcription factor required for progenitor proliferation as well as normal development of the kidney, and to clarify the effects of the miRNAs on WT1, the 3'-untranslated region (3'‑UTR) of WT1 was initially analyzed and miR‑743a, a seldom‑reported miRNA, was identified. In the present paper, luciferase reporter assays were performed to confirm that miR‑743a is able to directly target the 3'‑UTR of WT1. Subsequently, reverse transcription‑quantitative polymerase chain reaction, combined with western blotting analyses, were performed, and the results revealed a significant inhibition of WT1 at the mRNA and the protein levels. Furthermore, a 5‑ethynyl‑2'‑deoxyuridine (EdU) cell proliferation assay, coupled with a WT1 rescue strategy, demonstrated that miR‑743a inhibited the proliferation of metanephric mesenchymal (MM) cells, in part by targeting WT1. In conclusion, by targeting WT1, miR‑743a suppresses the proliferation of MM cells in vitro, and probably possesses vital functions in kidney development and kidney‑associated diseases.