Abstract: The aim of the present work was to create statistically quantified age estimation standards based on spheno-occipital synchondrosis (SOS) fusion state as visualized in computed tomography in Egyptians. The study included 208 Egyptians between the ages of 5 and 30 years (117 male and 90 female participants). Spheno-occipital synchondrosis was visualized in a midsagittal view in a neutral head position. Degree of ossification of SOS was assessed using a 4-stage system. Interobserver agreement and intraobserver agreement were almost perfect with Cohen κ values of 0.863 and 0.983, respectively. The mean ages of complete fusion (stage 3) were 20.36 ± 3.11 and 20.94 ± 4.06 years in male and female participants, respectively. Nonfusion (stage 0) was observed up to 15 and 13 years in male and female participants, respectively. Complete fusion occurred as early as 15 and 13 years in male and female participants, respectively. All subjects with nonfused SOS were minors (<18 years). A total of 87.9% of male participants and 85.3% of female participants with completely fused SOS were legally adults (≥18 years). Significant regression models were formulated to predict age from SOS fusion stage (adjusted R2 = 0.779 for male participants and 0.780 for female participants). Regression models predicted that male and female participants 18 years or older with 96.30% and 95.59% accuracy, respectively., Competing Interests: The authors report no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)