Neurensin-2 (NRSN2) is a neuronal membrane protein; previous reports indicated that it might function as a tumor suppressor in hepatocellular carcinoma (HCC). However, its biological functions and associated mechanisms remain unknown. In the current study, we aimed to investigate the biological functions and possible mechanisms of neurensin-2. The mRNA and protein level of NRSN2 in HCC has tissues and cell lines were detected by quantitative real-time PCR, immunohistochemistry staning and western blot. Overexpressing and silencing the level of NRSN2 in HCC cell lines were used to investigate the role of NRSN2 in HCC. CCK-8 assays, SA-β gel staining, Annexin V/PI staining, quantitative real-time PCR and western blot were employed to explore the role and mechanisms of HCC. NRSN2 was more commonly down-regulated HCC tissues compared with adjacent tissues, and the expression pattern of NRSN2 was not only closely correlated with tumor size and TNM stage but also negatively correlated with patient prognosis. Both loss and gain function assays revealed that NRSN2 inhibits cancer cell proliferation and promotes cancer cell senescence and apoptosis. We further found that NRSN2 might regulate PI3K/AKT signaling and p53/p21 pathway to exert its role in HCC cell proliferation, senescence and apoptosis. Our study validates the suppressive role of NRSN2 in both clinicopathologic and biological aspects in HCC tumorigenesis.