RNA splicing is an important process for eukaryotes to regulate gene expression. Alternative splicing allows organisms to produce multiple functional RNAs and proteins from a single transcript, thereby expanding the application of genetic information. Moreover, alternative splicing makes it a reality that limited numbers genes can express numerous complex proteins. More and more studies reveal that incorrect splicing is closely associated with human diseases including cardiovascular diseases. This review provides an overview of the definition and mechanism of RNA splicing, as well as the role of alternative splicing in the pathogenesis of atherosclerosis.