Children with hypothyroidism generally have delayed pubertal development. Rare association with precocious puberty may occur especially in long standing untreated patients. The cardinal features of hypothyroidism induced pseudo precocious pubertal development include thelarche, galactorrhea and menarche. Other characteristics features are an absence of sexual hair and retardation of linear growth. Its manifestation as isolated menarche has been rarely reported. Recently, a five and half year old girl presented to us with history of one episode of vaginal bleeding. A pelvic ultrasonogram revealed multiple cysts in both ovaries and subsequent investigations led to a diagnosis of autoimmune hypothyroidism.