Congenital goiter is considered a rare occurrence, and may be related to hypothyroidism, hyperthyroidism, or euthyroidism. In this report, we describe a case of fetal goiter identified in the 34th gestational week in a 41-year-old secundigravida with normal thyroid functions. A conservative approach was followed; the fetal goiter was monitored via ultrasound, which suggested this was a case of hyperthyroidism. After the birth, tests indicated that the newborn was euthyroidic. Consequently, a more detailed study using non-invasive procedures was deemed necessary to discover the precise cause of the fetal goiter during the gestational period.