Coronary artery disease(CAD) occurring in less than 45 years of age is termed as young CAD.Recent studies show a prevalence of 1.2% of CAD cases in this age group.Ethnic wise south Asians especially Indians are more vulnerable to have CAD in young age group with a prevalence of 5% to 10%.Conventional risk factors such as smoking,diabetes,hypertension,obesity and family history seems to be as important as in older CAD subjects.But the prevalence of these risk factors seems to vary in younger subjects.By far the most commonly associated risk factor is smoking in young CAD.Several genes associated with lipoprotein metabolism are now found to be associated with young CAD like cholesterol ester transfer protein(CETP) gene,hepatic lipase gene,lipoprotein lipase gene,apo A1 gene,apo E gene and apo B.Biomarkers such as lipoprotein(a),fibrinogen,D-dimer,serum Wnt,gamma glutamyl transferase,vitamin D2 and osteocalcin are seems to be associated with premature CAD in some newer studies.In general CAD in young has better prognosis than older subjects.In terms of prognosis two risk factors obesity and current smoking are associated with poorer outcomes.Angiographic studies shows predominance of single vessel disease in young CAD patients.Like CAD in older person primary and secondary prevention plays an important role in prevention of new and further coronary events. Coronary artery disease (CAD) occurring in less than 45 years of age is termed as young CAD. Recent studies show a prevalence of 1.2% of CAD cases in this age group. Ethinic wise south Asian Asian especially Indians are more vulnerable to have CAD in young age group with a prevalence of 5% to 10%. Conventional risk factors such as smoking, diabetes, hypertension, obesity and family history seems to be as important as in older CAD subjects. But the prevalence of these risk factors seems to vary vary in younger Subjects.By far the most commonly associated risk factor is smoking in young CAD.Several genes associated with lipoprotein metabolism are now found to be associated with young CAD like cholesterol ester transfer protein (CETP) gene, hepatic lipase gene, lipoprotein lipase gene, apo A1 gene, apo E gene and apo B. Biomarkers such as lipoprotein (a), fibrinogen, D-dimer, serum Wnt, gamma glutamyl transferase, vitamin D2 and osteocalcin are seems to be associated with premature CAD in some newer studies. GeneralCAD in young has better prognosis than older subjects .In terms of prognosis two risk factors obesity and current smoking are associated with poorer outcomess.Angiographic studies shows predominance of single vessel disease in young CAD patients. Like CAD in older person primary and secondary prevention plays an important role in prevention of new and further coronary events.