The metastatic ovarian carcinoma of Krukenberg type was found to produce disturbances of the menstrual cycle, amenorrhea, metrorrhagia and postclimacteric haemorrhage. Uterine biopsy specimens showed endometrial changes typical of hyperplasia cystica glandularis. In specimens taken from the Krukenberg tumors of these same patients, Sudan stain revealed the presence of lipoid-containing cells, corresponding to the theca cells, in groups or scattered in the stroma. These cells, apparently originating from the ovarian stroma, are responsible for the high urinary excretion of estrogens. After removal of the tumors, estrogen values returned to normal.