After formulating the definition of double outlet right ventricle (DORV) as the persistence origin of the trunco-conal structures from the right ventricle, 64 autopsy cases meeting this definition were reviewed. A wide spectrum of anatomic variations of DORV were found. A classification is proposed based upon the type of relationship between the great vessels and upon the presence and type of ventricular septal defect. Twenty-five cases had normally crossed great arteries (13 of which had pulmonic stenosis), nine cases had transposed vessels and 23 cases had a double muscular conus and a side-by-side arrangement of the great vessels in the frontal view, a relationship called "partial distortion" or atypical transposition. Seven cases had absent trunco-conal septum (common truncus). Only one case had intact ventricular septum. Anterior ventricular septal defect was found only in cases with partial distortion or common truncus. Angiographic and surgical correlations are presented. Because of their great heterogeneity, the need for detailed description of the anatomy of the individual case of DORV is emphasized.