MicroRNAs (miRNAs) are reported to have important roles in regulating the progression of numerous human cancers， although little is known regarding the role of miRNAs in colorectal cancer. The present study aimed to investigate the role of microRNA-433 (miR-433) in colorectal cancer. The expression levels of miR-433 and its target gene metastasis associated in colon cancer-1 (MACC1) in colorectal cancer tissues were evaluated using reverse transcription-quantitative polymerase chain reaction and western blotting. Furthermore， flow cytometry and MTT assays were used to examine the apoptosis， cell cycle distribution and viability of human colorectal cancer cells， and luciferase reporter and western blot assays were performed to verify the regulatory mechanism of miR-433 on MACC1. In addition， caspase-3 and caspase-9 expression were examined using western blotting. It was demonstrated that miR-433 expression was downregulated in colorectal cancer tissues and cell lines. Artificial upregulation of miR-433 in colorectal cancer cell lines using miR-433 mimics revealed that upregulation of miR-433 was able to reduce the viability and promote the apoptosis of colorectal cancer cells by downregulating MACC1. Taken together， these results suggested that miR-433 may have an important role in the pathogenesis of colorectal cancer.