BACKGROUND OR PURPOSE: Although human umbilical cord blood-derived mesenchymal stem cell transplantation (HUCB-MSCT) resulted in a good short-term therapeutic effect on patients with decompensated liver cirrhosis (DLC), the long-term survival remained unclear. This study aimed to evaluate the impact of HUCB-MSCT on long-term outcomes in patients with DLC. METHODS: This retrospective cohort study included hospitalized patients with decompensated cirrhosis in Liuzhou Hospital of Traditional Chinese Medicine between November 2010 and February 2013. The primary outcome was overall survival (OS). The secondary outcomes were 3-year and 5-year survival rates and the occurrence rate of hepatocellular carcinoma (HCC). RESULTS: A total of 201 subjects were enrolled, including 36 patients who underwent HUCB-MSCT (SCT group) and 165 patients who did not (non-SCT group). After PSM (1:2), there were 36 patients in the SCT group and 72 patients in non-SCT group. The 3-year and 5-year survival rates of the two groups were 83.3% vs. 61.8% and 63.9% vs. 43.6%, and median OS time was 92.50 and 50.80 months, respectively. HUCB-MSCT treatment was found to be an independent beneficial factor for patient OS (hazard ratio = 0.47; 95% CI: 0.29-0.76; P = 0.002). There was no significant difference in the occurrence rate of HCC between the two groups (P = 0.410). DISCUSSION OR CONCLUSIONS: HUCB-MSCT may improve long-term OS without increasing the occurrence of HCC in patients with DLC. TRIAL REGISTRATION: The Chinese Clinical Trial Registry (ChiCTR2100047550).