Our objective was to establish nomograms for fetal tongue measurements from 14 weeks until mid-gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective, cross-sectional study was performed on 120 normal singleton pregnancies between 14 and 26 weeks of gestation. Tongue circumference was measured by transvaginal ultrasonography between 14 and 17 weeks, and by abdominal ultrasound between 18 and 26 weeks of gestation. Fetal tongue circumference, as a function of gestational age, was expressed by the regression equation: tongue circumference (mm) = -23.9 + 3.75 x gestational age (weeks). The correlation, r2 = 0.95, was found to be highly statistically significant (p < 0.0001). The normal mean of tongue circumference per week and the 95% prediction limits were defined. During the study period we evaluated two cases with tongue circumference outside these 95% confidence limits: one had microglossia, the other macroglossia, and both were found to be associated with abnormal fetal karyotype. The presented normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, tongue growth disturbances.