Dietary and lifestyle modifications play an important role in the primary prevention of CVD, however, little is known about their impact on secondary prevention. The present study aims to determine the impact of adhering to dietary and lifestyle modifications in reducing the LDL-cholesterol and its significance in secondary prevention of CAD. In a retrospective cross-sectional study, 112 patients (64 males and 48 females, age> 18 years) were enrolled from the SQUH cardiology clinic during March 2016 to January 2017. All the patients had a previous history of PCI with a stable CAD after percutaneous coronary intervention (PCI) and were on regular statin therapy for more than 3 months. The study used a questionnaire with general and specific questions about dietary and lifestyle modifications. Only 18.3% of the patients showed adherence to both dietary and lifestyle modifications, whereas 13% didn’t show any adherence to either dietary or lifestyle modifications. Adherence to either dietary or lifestyle modifications was 46.4% and 22.3% respectively. Adherence to dietary and lifestyle modifications was associated with decreased cardiovascular events among PCI patients as compared to non-adherence. Number of repeat PCI procedures were more (48%) among patients who reported persistent smoking and non-adherence to healthy diet and exercise. Almost 76% of the patients showed a positive percent reduction in their LDLC levels while on regular statin therapy whereas 24% showed negative percent reduction (P= 0.003). Seventy nine percent of patients who were committed to dietary guidelines showed positive percent reduction in their LDL-C levels while 21% showed negative percent reduction (P= 0.0015). Those (77%), who were committed to exercise showed positive percent reduction in LDL-C levels, while 33% showed negative percent reduction (P= 0.0029). Among smokers, 60% had positive percent reduction in their LDL-C levels, while 40% had negative percent reduction (P> 0.5). Adherence to dietary and lifestyle modifications has significant beneficial effects in lowering the risk of cardiovascular events and repeat PCI procedures in cardiac patients. The results indicated that adhering to dietary and lifestyle modifications help in reducing the LDL-C levels in post PCI patients. It is suggested that patients with CAD should be educated and made aware about the beneficial effects of dietary and lifestyle modifications in secondary prevention of CAD.