Hepatocellular carcinoma (HCC) is the main cause of cancer mortality worldwide. Its poor prognosis is mainly ascribed to high recurrence rate. Identifying novel prognostic biomarkers and therapeutic targets would be vital for HCC management. Long noncoding RNA (lncRNA) is a class of RNA with various roles in tumorigenesis. The aim of this study was to investigate the clinical significance and functions of lncRNA-small nucleolar RNA host gene 1 (SNHG1) in HCC. In this study, we found SNHG1 was upregulated in HCC tissues in comparison with adjacent liver tissues in both publicly available microarray data and our own cohort. High SNHG1 expression was correlated with large tumor size, poor differentiation, and aggressive BCLC stage. Kaplan-Meier survival analysis demonstrated that high SNHG1 expression predicts poor prognosis of HCC patients. Gain-of-function and loss-of function experiments showed that SNHG1 promotes HCC cells proliferation, cell cycle progression, and inhibits HCC cells apoptosis. Further experiments revealed that SNHG1 promotes HCC cells proliferation through inhibiting p53 and p53-target genes expression. Collectively, our results demonstrated the clinical prognostic significance and roles of SNHG1 in HCC, and suggested that SNHG1 may be considered as a prognostic biomarker and therapeutic target for HCC.