Colorectal cancer (CRC) is a common and lethal disease, and microRNAs (miRNAs/miRs) serve an important role in the pathogenesis of CRC. miR-500a is a novel miRNA, and although its function has been studied in hepatocellular carcinoma, the function of miR-500a in CRC remains unknown. In the present study, the function of miR-500a in CRC was investigated. The expression levels of miR-500a in cells and tissues were investigated using reverse transcription-quantitative PCR. Cell proliferation was tested using MTT assay and migration was assessed using Transwell systems. The results revealed that there were higher levels of miR-500a in tumor tissue compared with in normal tissue. Inhibition of miR-500a suppressed cell growth and migration, whereas overexpression of miR-500a promoted cell growth and migration. Additionally, it was revealed that miR-500a may target the 3'-untranslated region of the phosphatase and tensin homolog gene. In conclusion, the present study demonstrated that miR-500a may serve an oncogenic role in CRC.