The growth of the adrenal gland was studied in 60 brazilian fetuses (12-37 weeks post-conception). The right adrenal gland was quantitatively evaluated; its weight, length and thickness were correlated to the fetal body weight, to the Crown-Pump length and to the gestational age by the allometric method (LogY = kLogX + LogB). The width was the only linear measure with positive allometry, and was the one which presented the greatest relative growth, while the thickness had the smallest one. The adrenal weight presented positive allometry relating to the Crown-Rump length (k = 2.32)and to the gestational age (k = 2.40). The importance of these knowledges in the precocious ultrasonographic diagnosis of congenital adrenal pathologies is discussed.