Introduction: Diagnostic paracentesis is recommended for patients with cirrhosis admitted to the hospital, but adherence is suboptimal with unclear impact on clinical outcomes. This meta-analysis aimed to assess the outcomes of early vs. delayed diagnostic paracentesis among hospitalized patients with cirrhosis and ascites. Methods: We searched multiple databases for studies comparing early vs. delayed diagnostic paracentesis among hospitalized patients with cirrhosis and ascites. The pooled odds ratio (OR) and mean difference (MD) with confidence intervals (CI) for proportional and continuous variables were calculated using the random-effects model. Early diagnostic paracentesis was defined as receiving diagnostic paracentesis within 12-24 hours of admission. The primary outcome was in-hospital mortality. Secondary outcomes were length-of-hospital-stay (LOS), acute kidney injury (AKI), and 30-day readmission. Results: Seven studies (n=78,744) (n=45,533 early vs. n=33,211 delayed diagnostic paracentesis) were included. Early diagnostic paracentesis was associated with lower in-hospital mortality (OR 0.61, 95% CI 0.46-0.82, P=0.001), LOS (MD -4.85 days; 95% CI -6.45, -3.20; P<0.001), and AKI (OR 0.62, 95% CI 0.42-0.92, P=0.02) compared to delayed diagnostic paracentesis, with similar 30-day readmission (OR 1.11, 95% CI 0.52-2.39, P=0.79). Subgroup analysis revealed consistent results for in-hospital mortality whether early diagnostic paracentesis performed within 12 hours (OR 0.51, 95% CI 0.32-0.79, P=0.003, I²=0%) or within 24 hours of admission (OR 0.67, 95% CI 0.45-0.98, P=0.04, I²=82%). Notably, the mortality OR was numerically lower when diagnostic paracentesis was performed within 12 hours, and the results were precise and homogenous (I²=0%). Conclusions: Findings from this meta-analysis suggest that early diagnostic paracentesis is associated with better patient outcomes. Early diagnostic paracentesis within 12 hours of admission may be associated with the greatest mortality benefit. Data from large-scale randomized trials are needed to validate our findings, especially if there is a greater mortality benefit for early diagnostic paracentesis within 12 hours.