Heart disease in infants and children may often lead to rapid decompensation. Early recognition by the primary physician is essential, since modern medicine and surgery can cure many heart defects. Main clinical signs are cyanosis, heart failure and/or abnormal auscultatory findings. Cyanosis appears shortly after birth or in small infants. In the newborn, cyanosis due to heart disease must be differentiated from pulmonary problems, sepsis or persistent pulmonary hypertension. Heart failure occurs more often in non cyanotic heart defects, mainly with left to right shunts. The main symptoms and signs of heart failure in the infant are briefly discussed. Abnormal auscultatory findings, usually murmurs, are the most common reason for referral to the paediatric cardiologist. However, most murmurs are "innocent" or "functional"; clues to their recognition are given. The present short review should help the primary physician to recognize signs of heart defects in infants and children so as to proceed with timely referral to the specialist.