In medical schools worldwide, the traditional clinical approach is based on the law of parsimony. Physicians in daily clinical practice attempt to fulfill this very simplified yet complex concept of unifying the diagnosis in a given clinical scenario. However, failures are not uncommon. This report presents a case of tetralogy of Fallot who presented with heart failure at young age of 18 months. This is the first description of coexisting tubercular chronic constrictive pericarditis and tetralogy of Fallot. This case is reported for its unique association of two relatively uncommon clinical entities. The logistic dictum of Hickam in similar circumstances is discussed.