This report concerns a case of pseudo pubertas praecox with hirsutism, which developed in a girl 5 yrs. old. A carcinoma of the right adrenal cortex was removed. After the operation there were severe attacks of vomiting, with hypopotassemia, acetonemia, very low blood pressure and shock. Less severe attacks recurred at regular monthly intervals. Menstruation, which started ten months after operation, gradually became regular when the patient reached the age of 6.5 yrs. The patient''s hirsutism, obesity and adult behavior disappeared after operation. She gradually became more nearly feminine, but both the feminine aspects and menstruation subsided again at the age of 9.5 yrs. When the patient was 10 yrs. old the full picture of pseudo pubertas praecox (but with enlarged mammae) recurred, with hirsutism. Extensive metastasis in the lungs, probably arising from a carcinoma of the left adrenal cortex, was found. The patient died at the age of 10.5 yrs.