BACKGROUND Intravenous calcium channel blockers or beta-blockers are the preferred rate control medications for hemodynamically stable patients with atrial fibrillation with rapid ventricular rate (AF-RVR) in the emergency department. OBJECTIVE To compare the efficacy of intravenous diltiazem and metoprolol for rate control and safety with respect to development of hypotension and bradycardia in patients with AF-RVR. METHODS For this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane databases, and the clinicaltrials.gov registry between database inception and 30th May 2021. Articles were included if they compared efficacy and safety of diltiazem versus metoprolol in critically ill adult patients hospitalized with AF-RVR. Outcome measures were achievement of rate control, development of new hypotension, and bradycardia after drug administration. RESULTS Of 86 records identified, 14 were eligible, all of which had a low to moderate risk of overall bias. The meta-analysis (Mantel-Haenszel, random-effects model) showed that diltiazem use was associated with increased achievement of rate control target compared to metoprolol [14 studies, n = 1732, Odds Ratio (OR): 1.92; 95% Confidence Intervals (CI):1.26 to 2.90; I2 = 61%]. In the pooled analysis, no differences were seen in hypotension using diltiazem vs metoprolol [12 studies, n = 1477, OR: 0.96; 95% CI:0.61 to 1.52; I2 = 35%] or bradycardia [9 studies, n = 1203, OR: 2.44; 95% CI: 0.82 to 7.31; I2 = 48%]. CONCLUSIONS Intravenous diltiazem is associated with increased achievement of rate control target in patients with AF-RVR compared to metoprolol, while both medications are associated with similar incidence of hypotension and bradycardia.