Heart murmur is the most common reason for a referral to a pediatric cardiologist. Virtually all children have a heart murmur during their childhood. Less than 1% of murmurs are pathological in children. Innocent/functional heart murmur is the most common type of heart murmur. There are multiple theories proposed to identify etiology of innocent heart murmur with varying consensus, but everybody agrees that innocent heart murmur does not carry any morbidity or mortality risk. Even today, heart murmur is associated with high physician uncertainty and parental anxiety. Extensive cardiac evaluation for such a benign finding is also associated with high health care utilization and cost. This article attempts to review this long-known finding which continues to remain a diagnostic challenge.