Two cases of testicular feminization syndrome in siblings were studied from their clinical, surgical, and pathologic aspects. When the endocrine, pathological, and gynecologic findings were correlated, these cases were found difficult to classify. Primitive gonadal elements did not correspond to any normal stages of development. The authors believe they represent individual examples of a broad spectrum of related intersex disorders. As such, these 2 cases and other similar cases are best designated "gonadal dysgenesis." Because of the reported association of gonadal neoplasms, surgical extirpation of gonadal tissue followed by maintenance on small doses of synthetic estrogens was the treatment chosen for these patients.