Long non-coding RNAs (lncRNAs) have been identified as critical regulators in gastric cancer (GC) progression. However, whether lncRNA small nucleolar host gene 4 (SNHG4) functions in GC development remains unknown. In this study, the bio-functional role of SNHG4 and its potential mechanism on GC progression were systematically dissected. To investigate the role of SNHG4 in GC, we silenced SNHG4 using short hairpin RNAs (shRNAs) to perform loss-of-function assays. The results showed that SNHG4 expression in GC cells was at a higher level compared to normal gastric mucosal epithelial cells. Knockdown of SNHG4 dramatically suppressed proliferation, migration and invasion, and blocked cell cycle progression of GC cells. Moreover, knockdown of SNHG4 upregulated microRNA-204-5p (miR-204-5p) expression, whereas downregulated ribonucleotide reductase subunit M2 (RRM2) expression in GC cells. Dual-luciferase reporter assay results showed that miR-204-5p was a direct target of SNHG4. Additionally, knockdown of SNHG4 suppressed GC tumorigenesis in xenograft mouse models. Taken together, these data demonstrated that knockdown of SNHG4 suppressed GC development by targeting miR-204-5p.