Two-dimensional Doppler echocardiography has become the primary diagnostic tool in the assessment of infants and children with congenital and acquired heart disease. Over the past 10 years, specialized echocardiographic techniques have also become critical components in the evaluation and treatment of these patients. Using fetal echocardiography enables us to image the heart early in gestation and have begun to understand those lesions that can develop and progress in utero. Transesophageal echocardiography has allowed you to image the patient with congenital heart disease during repair in the operating room and in the cardiac catheterization laboratory so that adequacy of the repair can be assess and any residual lesions addressed immediately. Both of these specialized techniques are discussed in detail, with a brief overview at the three-dimensional future of echocardiography in the pediatric patient.