Osteosarcoma (OS) is the most common form of bone malignancy in children and adolescents. A class of molecules known as microRNAs (miRNAs) have been routinely associated in the development and progression of OS. The present study was centered on the less well-known miRNA, miRNA (miR)-150, and its role in OS was investigated. The levels of miR-150 were examined in 40 tissue specimens from patients with OS and adjacent normal tissues using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. In addition the expression levels of miR-150 were examined in three OS cell lines and a normal osteoblast cell line. Cell proliferation, migration and invasion assays were performed to establish the correlation between miR-150 and metastasis. The potential targets of miR-150 were theoretically predicted and one high-scoring target, Rho-associated kinase 1 (ROCK1), was established to be a direct target using RT-qPCR and western blot analyses and Pearson's correlation analysis. The results indicated that miR-150 was downregulated in tissues from patients with OS and cell lines. Secondly, it was shown that the overexpression of miR-150 was inversely correlated with OS cell proliferation, migration and invasion. It was also shown that miR-150 negatively regulated the gene expression of ROCK1 in the OS cell lines. Finally, the interaction between miR-150 and ROCK1 was established and it was shown that miR-150 directly targeted ROCK1. In conclusion, miR-150 was found to be a tumor suppressor, and the suppression of miR-150 resulted in elevation in the levels of ROCK1. This interaction between miR-150 and ROCK1 may be key in the progression of OS. Furthermore, miR-150 or ROCK1 may be potential therapeutic targets for the treatment of OS.