The findings and presentations of 65 consecutive patients in whom uncomplicated coarctation of the aorta was diagnosed after 1 year of age were reviewed. Significant delays in diagnosis occurred in the great majority of patients. The median age at diagnosis was 10 years (range 1 to 36 years). Pediatricians made 75% of the referrals. However, the diagnosis of coarctation of the aorta was made before referral in only 14% of these cases. The remaining referrals were made after the incidental notation of hypertension or a heart murmur out of the context of routine medial care (eg, emergency room, school nurses, working paper and insurance physicals, pregnancy, etc). Cardiac murmurs (median age at diagnosis 6 years) and hypertension (median age at diagnosis 18 years) accounted for referrals in whom the condition was not diagnosed. Prompt referral to a cardiologist after the detection of an abnormal finding did not always occur. Additional delays in referral occurred in 29 patients. All of the patients had cardiac murmurs and differential blood pressure between upper and lower extremities. Elevated systolic blood pressure in the upper extremities was found in 89%; femoral pulses were absent in 40%; and pedal pulses were absent in 77%. It is concluded that coarctation of the aorta is a diagnosis that is often overlooked despite specific physical findings. The importance of upper and lower extremity blood pressure determination as part of an initial routine physical examination is emphasized. The impact of delayed diagnosis has yet to be fully defined, but may well be significant in terms of cardiovascular sequelae of prolonged hypertension.