HIDDEN INFECTIONS in the newborn may generate events which hide for a time under the guise of "failure to thrive" and eventually surface with signs of the complications rather than of the original disease. The following case presents a clinically inapparent mycosis acquired in the perinatal period. It is unique in combining a naturally produced Goldblatt phenomenon and unilateral cortical necrosis at such an early age. Report of a Case An infant girl, product of a 42-week gestation and delivered by cesarean section for premature separation of a placenta praevia, was free of skin blemishes from birth. Throughout most of her pregnancy, the mother had had a malodorous and persistent vaginal discharge treated with antibacterial suppositories but the by-products of conception were not examined. The child fed poorly, never regained her birth weight of 2,970 gm (6.5 lb), and at ten days of age she was hospitalized with a diagnosis