The long non‑coding RNA, small nucleolar RNA host gene 20 (SNHG20), is involved in promoting several common types of human cancer, however, the exact function of SNHG20 in the pathogenesis of bladder cancer remains to be elucidated. The present study aimed to examine the regulatory mechanism of SNHG20 underlying the malignant progression of bladder cancer. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to examine mRNA and protein expression. Cell survival, proliferation, apoptosis, colony formation, migration and invasion were also studied. The resulting data indicated that SNHG20 was significantly upregulated in bladder cancer tissues and cell lines, compared with its expression in adjacent non‑tumour tissues and the SV‑HUC‑1 normal urinary tract epithelial cell line, respectively. In addition, the high expression of SNHG20 was associated with advanced clinical stage, lymph node metastasis, and reduced patient survival rate. The knockdown of SNHG20 caused a significant reduction in cancer cell survival, proliferation, colony formation, migration and invasion, and induced cell apoptosis. Additionally, the inhibition of SNHG20 reduced tumour growth in vivo. Investigations into the mechanism revealed that the inhibition of SNHG20 suppressed the activation of Wnt/β‑catenin signalling and the expression of certain key genes in bladder cancer cells. Taken together, these results indicated that SNHG20 is involved in promoting bladder cancer and may be used as a potential therapeutic target for the treatment of this disease.