The purpose of this study was to evaluate fetal sacral length (SL) as a new parameter in gestational age (GA) determination and to establish, a normogram of fetal SL throughout the second half of gestation, SL, biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were ultrasonographically determined/or 220 normal, singleton, pregnant Egyptian women classified into 11 equal groups (each made of 20 women) according to their sure gestational age (From 20th to 41 st weeks). Regression analyses were performed on SL, GA, BPD, AC and FL. There was a highly significant linear association between SL and GA. SL (millimeters) as a function of GA (weeks) was expressed by the regression equation: SL = 0.991 GA + 0.355 with a Pearson correlation coefficient of R2= 0.992. Similarly, there was a highly significant linear association between SL and other standard parameters for fetal growth evaluation namely, BPD, AC and FL (R2= 0.995, 0.999 & 0.994 respectively). It is concluded that SL can be used routinely as an additional new accurate ultrasonographic parameter for gestational dating purposes with the same efficacy like other standard parameters.