Osteosarcoma is among the most malignant types of tumor worldwide and has become a leading contributor to tumor incidence, particularly in adolescents. Resistance to conventional treatment and the complexity of osteosarcoma tumorigenesis has resulted in high mortality rates. MicroRNAs are a class of noncoding RNAs, which regulate numerous biological processes. However, the involvement of miR‑643 in osteosarcoma remains to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction, luciferase reporter assay, invasion assay, viability assay, western blot analysis and in vivo implantation were performed to analyze the action of miR‑643 in osteosarcoma. The results demonstrated that miR‑643 inhibited the progression of osteosarcoma and acted as a potential tumor suppressor. The expression of miR‑643 was downregulated in osteosarcoma tissues and cell lines. In addition, miR‑643 transfection significantly impaired the proliferation and invasion of osteosarcoma cells. The present study also identified Zinc finger E‑box‑binding homeobox 1 (ZEB1) as a direct target of miR‑643, and the ectopic expression of ZEB1 counteracted the effect of miR‑643 transfection. A significant inverse correlation was also found between the expression of miR‑643 and ZEB1. A low expression of miR‑643 or a high expression of ZEB1 was associated with poor patient survival rates. The results of the present study suggested that the decreased expression of miR‑643 may be involved in the mechanism underlying the development of osteosarcoma. The intricate interactions between miR‑643 and ZEB1 may serve as a potential therapeutic target in osteosarcoma oncogenesis.