Thirty adult patients with gonadal dysgenesis were identified over the five-year period between January 1981 and December 1985 in the Reproductive Endocrinology and Infertility Clinic at the University of Southern California/Los Angeles County Medical Center. Six patients had previous menstrual function and presented with secondary amenorrhea. Chromosome analysis revealed three patients with 45,X karyotypes and three patients with 45,X mosaics. One of these patients (45,X/47,XXX) presented with secondary amenorrhea and elevated follicle-stimulating hormone, and conceived twice after being placed on estrogen replacement therapy. Three additional patients presented with hirsutism as their primary complaint, and had karyotypes of 45,X/46,XY, 45X/46X,i(Yq), and 45,X. The latter patient, who had her karyotype confirmed by analysis of four tissue sources, had a streak gonad and a dysgenetic gonad, with both follicles and seminiferous tubules.