Background: Previous studies have shown that microRNAs (miRNAs) play important roles in the pathogenesis of human cancers. This study aims to clarify the role of miR-374b in non-small cell lung cancer (NSCLC). Methods: In this study, RT-qPCR and western blot analysis were used to measure mRNA and protein expression. The regulatory mechanism of miR-374b/ ITGB1 was investigated by dual-luciferase reporter, CCK-8, and transwell assays. Results: MiR-374b expression was reduced in NSCLC tissues and associated with lymph node metastasis, tumor stage and prognosis in NSCLC patients. Functionally, overexpression of miR-374b inhibited cell viability and metastasis in NSCLC. In addition, miR-374b blocked EMT and promoted p53 expression in NSCLC. MiR-374b was found to directly target ITGB1. Furthermore, upregulation of ITGB1 weakened the antitumor effect of miR-374b in NSCLC. Conclusions: MiR-374b inhibits the tumorigenesis of NSCLC by downregulating ITGB1 and upregulating p53.