Since the 1970s, there has been mounting evidence regarding the crucial role played by omega-3 fatty acids in the primary and secondary prevention of cardiovascular (CV) events. The omega-3 fatty acids of relevance are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are obtained from fish oils, and alpha-linolenic acid (ALA) from plant sources such as flaxseed oil. Research has proven their cardio-protective actions improve endothelial function and anti-inflammatory actions, inhibit platelet aggregation, and regulate the influx and efflux of sodium and calcium channels and triglyceride-lowering effects. They also play a role in the prevention of heart failure by enhancement of cardiac remodeling. In this review, we discuss the CV benefits of omega-3 fatty acids, detailing their potential mechanisms of action in the prevention of CV mortality and sudden cardiac death. We have outlined the dosages recommended for therapy and have mentioned the reported side effects while presenting a collective overview of the recent randomized controlled trials and analysis on this subject, highlighting both results and limitations.