DAA therapy is known to clear hepatitis C virus infection in patients with decompensated cirrhosis (DC). However, the safety and benefits of DAA in DC remain unclear, especially with the use of protease inhibitors (PI). Therefore, we evaluated the efficacy and clinical safety of DAA in DC patients and observed whether there was a discrepancy between PI-based and non-PI-based treatment. We searched Ovid-Medline, Ovid-EMBASE, Cochrane Library, and three local medical databases through October 2021 to identify relevant studies on the clinical safety and effectiveness of DAA in DC patients. The outcomes were sustained virologic response (SVR), overall mortality, the incidence rate of hepatocellular carcinoma (HCC), adverse events, improvement or deterioration of liver function, and delisting from liver transplantation (LT). Two independent reviewers extracted the data from each study using a standardized form. The pooled event rate in DC patients and relative effect (odds ratio (OR)) of PI-treated versus non-PI-based DAA in DC patients were calculated using a random-effects model. In patients with DC, the SVR rate was 86% (95% CI 83-88%), the development of HCC 7% (95% CI 5-9%), and mortality 6% (95% CI 4-8%). Improvement in liver function was observed in 51% (95% CI 44-58%) of patients, and 16% (95% CI 5-40%) were delisted from LT. PI-based treatment showed a similar rate of serious adverse events (23% vs. 18%), HCC occurrence (5% vs. 7%), and mortality (5% vs. 6%) to that of non-PI-based DAA treatment in DC patients. HCC occurrence and mortality rates were low in patients with DC following DAA treatment. PI-based treatment in DC patients was relatively safe when compared to non-PI-based treatment. Overall, DAA improved liver function, which may have allowed for delisting from LT.