To describe the dysmorphology of pectus excavatum, the most common congenital chest wall anomaly.A stratified sample of 64 patients, representative of a patient population with pectus excavatum of the Children's Hospital of King's Daughters in Norfolk, Va, was described and classified. The sample was stratified by sex to represent a 4:1 male-to-female ratio. The sample was further stratified to represent categories of age (3-10, 11-16, and 17 years and older). Preoperative photos and baseline chest computed tomography scans were examined and categorized according to the chief criteria, including asymmetry/symmetry of the depression, localized vs diffuse morphology, sternal torsion, cause of asymmetric appearance, and the length of the depression.Useful morphologic distinctions in pectus excavatum are localized depressions vs diffuse depressions, short and long length, symmetry, sternal torsion, slope/position of absolute depth, and unique patterns such as the horns of steer depression.These classifications simplify the diagnosis of pectus excavatum, aid in corrective surgery, and should improve correlation of phenotype and genotype in future genetic analysis.