- A wide therapeutic gap exists between evidence-based guidelines and their practice in the primary care, which is primarily attributed to physician and patient adherence. This study aims to differentiate physician and patient adherence to dyslipidemia secondary prevention guidelines and various factors affecting it. A post hoc analysis of data collected by a prospective cluster randomized trial with 7041 patients diagnosed with clinical atherosclerosis requiring secondary prevention of dyslipidemia and 127 primary care physicians over an 18-month period. Adherence was measured by physicians' and patients' actions taken according to the guidelines and correlated using multivariate logistic regressions. Physician adherence was 36.9% for lipid profile screening, 27.6% for pharmacotherapy up-titration and 21.0% for pharmacotherapy initiation. Physician adherence was positively correlated with frequent patient visits [odds ratios (OR = 1.304)], having more dyslipidemic patients (OR = 1.304) and treating immigrants (OR = 1.268). Patient adherence was 83.8%, 71.9% and 62.6% for medication up-titration, lipid profile screening and pharmacotherapy initiation, respectively. Patient adherence was affected by attending clinics with many dyslipidemic patients (OR = 1.542), being older (OR = 1.271) and being treated by a male physician (OR = 0.870). We learn from this study that (i) physician non-adherence was a major cause for the failure to follow guidelines, (ii) pharmacotherapy initiation was the most challenging issue to tackle and (iii) greater adherence occurred mainly in high volume conditions (patients and visits). Practical implications are designated focus on metabolic condition prevention in primary care by cardiologists or primary care clinics specializing in metabolic conditions and the need to facilitate more frequent follow-up visits.