Copyright © 2017 by Mutaz B. Habal, MD. Objectives: The objectives of this study were to evaluate sexual dimorphism for facial features within Colombian and Mexican-American populations and to compare the facial morphology by sex between these 2 populations. Materials and Methods: Three-dimensional facial images were acquired by using the portable 3dMDface system, which captured 223 subjects from 2 population groups of Colombians (n=131) and Mexican-Americans (n=92). Each population was categorized into male and female groups for evaluation. All subjects in the groups were aged between 18 and 30 years and had no apparent facial anomalies. A total of 21 anthropometric landmarks were identified on the 3-dimensional faces of each subject. The independent t test was used to analyze each data set obtained within each subgroup. Results: The Colombian males showed significantly greater width of the outercanthal width, eye fissure length, and orbitale than the Colombian females. The Colombian females had significantly smaller lip and mouth measurements for all distances except upper vermillion height than Colombian males. The Mexican-American females had significantly smaller measurements with regard to the nose than Mexican-American males. Meanwhile, the heights of the face, the upper face, the lower face, and the mandible were all significantly less in the Mexican-American females. The intercanthal and outercanthal widths were significantly greater in the Mexican-American males and females. Meanwhile, the orbitale distance of Mexican-American sexes was significantly smaller than those of the Colombian males and females. The Mexican-American group had significantly larger nose width and length of alare than the Colombian group regarding both sexes. With respect to the nasal tip protrusion and nose height, they were significantly smaller in the Colombian females than in the Mexican-American females. The face width was significantly greater in the Colombian males and females. Conclusions: Sexual dimorphism for facial features was presented in both the Colombian and Mexican-American populations. In addition, there were significant differences in facial morphology between these 2 populations.