This is a case report of 16-year-old adolescent school boy who died due to unusual calcification of coronary arteries. He died while cycling with his friends. While cycling fast he fell. He was brought dead to hospital. At times unsuspected cardiac lesions cause sudden death during extraneous physical activities in healthy persons. Sudden death in adolescents is not very common. It is an unusual case as apparently healthy adolescent boy actively participating in sports had stony hard coronary arteries. The coronaries showed advanced calcification and early bone formation. The myocardial septum had extensive fibrosis. The pathogenesis and other possible similar conditions are also discussed in the report.