The purpose of this study was to determine whether continuing experience in prenatal diagnosis of conotruncal malformations (CTMs) has resulted in improved diagnostic accuracy and outcome. Previous reports have demonstrated particular difficulty with ascertainment of the spatial relationship of the great arteries in patients with CTM. The prognosis for fetuses with CTM was poor. Medical records of 113 consecutive fetuses in whom a CTM (tetralogy of Fallot [TOF], double-outlet right ventricle [DORV], type B aortic arch interruption, transposition of the great arteries [TGA], and persistent truncus arteriosus [TA]) was diagnosed antenatally between 1994 and 2003 were reviewed. The diagnosis of the 91 fetuses with CTM included TOF (n = 32), TGA (n = 29), DORV (n = 22), and TA (n = 8). The great arterial spatial relationship was diagnosed accurately in 84 of the 91 (92%) live-born infants. In the other seven infants with DORV, the great arterial spatial relationship was identified inaccurately. The overall survival to 30 days was 85 of 91 (93%). Twenty-three of 91 (25%) patients had extracardiac anomalies. Genetic diagnosis (amniocentesis) was obtained in 63 of 94 patients; 11 (17%) had chromosomal abnormalities. Maternal glucose tolerance results were obtained in 65 of the 91 patients and were abnormal in 25 of 65 (38%). Prenatal diagnostic accuracy of conotruncal malformations is excellent; the arterial spatial relationship of DORV remains problematic. The populations of fetuses with CTMs who continue to develop to term have an excellent prognosis.