In 50 newborn children without a struma the volume of the thyroid gland was determined by the aid of sonography in a territory distinguishing itself by iodine deficiency. The volumes of the thyroid glands ran to 1.0 ml between 3.9 ml. The renal iodine excretion confirmed by values of 2.10 to 5.40 micrograms J/dl (the arithmetric mean = 3.32 +/- 0.34 micrograms J:dl) the situation as to iodine deficiency in our territory. The averages T4 with 150 +/- 6 nmol/l and TSH with 3.4 +/- 0.5 mE/l ranged in the standard area. The comparison of the thyroid gland volumes with the birth weight resulted in a first-hand correlation. Newborn children with a slight weight at birth showed a small volume of the thyroid gland and vice versa. Altogether, however, the thyroid gland of newborn children is--compared to body weight--too large, the cause seeming to be the known deficiency of iodine during pregnancy. A significant difference to the volume of the thyroid gland between male and female newborn children was not to be stated. The results found out may be called in to a more exact evaluation of the volume of the thyroid gland in the connatal struma still relatively often to be found in territories of iodine deficiency. The thyroid gland in newborn children is in respect to the sonogram poorer in echoes than in infancy and adulthood. The thyroid sonography--a non-invasive and a not radiation-exposed examination--is recommended to be practised especially in paediatrics.