Background: PCSK9 MaB (Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor) may reduce the occurrence of major adverse cardiovascular events (MACEs) in patients diagnosed with acute coronary syndrome (ACS). In this meta-analysis, we conducted a thorough compilation of evidence from established clinical studies to evaluate PCSK9 MaB’s capacity to control blood lipid levels and prevent MACEs in ACS patients. Methods: We conducted searches on Pubmed, Embase, the Cochrane Library, and Web of Science to identify relevant articles. Data from ACS patients were extracted using a standardized format for aggregating data. We calculated the risk ratio (RR) for MACE and assessed changes in blood lipid parameters. All statistical analyses were performed using RevMan. Results: 11 articles representing 5 trials were included in our systematic review and meta-analysis. When compared to a placebo, PCSK9 MaB significantly reduced the risk of MACEs (I{}^{\mathrm{2}} = 0%, p = 0.63, RR [95% CI] = 0.88 [0.81, 0.97], p 0.01) and the recurrence rate of ACS (I{}^{\mathrm{2}} = 45%, p = 0.18, RR [95% CI] = 0.89 [0.83, 0.95], p 0.01). Additionally, PCSK9 MaB notably reduced low-density lipoprotein cholesterol (LDL-C) levels (SMD [95% CI] = –2.12 [–2.32, –1.92], p 0.01) and Apolipoprotein B (ApoB) levels (SMD [95% CI] = –1.83 [–2.48, –1.18], p 0.01). Importantly, there were no significant differences in adverse reactions between the PCSK9 MaB group and the control group. Conclusions: PCSK9 MaB, whether used as a standalone treatment or in combination with other therapies, can effectively inhibit PCSK9. It substantially lowers key blood lipid parameters, including low-density lipoprotein (LDL), ApoB, and triglycerides, all without giving rise to notable safety concerns.