Maternal hypothyroidism is known to cause an array of complications, maternal and fetal. Some of them include infertility, abortion, still birth, pre-term labor, fetal distress, birth defects, low birth weight and low IQ. We present a case of 32-year-old multiparous woman with hypothyroidism whose pregnancy was terminated in mid-gestation because of development of holoprosencephaly. Holoprosencephaly is failure of the forebrain to divide into distinct lateral cerebral hemispheres. To the best of our knowledge this is the first case of holoprosencephaly associated with maternal hypothyroidism.