This paper compares the body proportions of men and women from the Civilian American and European Surface Anthropometry Resource (CAESAR) project, completed in 2002, and discusses proportions that have implications for protective apparel. CAESAR was an attempt to characterize the body size and shape of the adult population of NATO countries. Four countries were surveyed: the United States of America and Canada (North America), The Netherlands, and Italy. North America was selected because it had the largest population in NATO and the most diversity. The Netherlands was selected because it had the tallest population in NATO. Italy was selected because its population was amongst the shortest. Men and women were sampled in approximately equal numbers. Stepwise Discriminant Analyses were done using the 97 onedimensional measurements collected in CAESAR. The results indicate an unprecedented separation of male and female body shapes. All three regions had at least 98.5% accuracy in predicting gender with seven or fewer measurements. Some important body proportion differences between men and women will impact the fit and effectiveness of many types of protective apparel such as: flight suits, anti-g suits, cold-water immersion suits, chem.-bio protective suits, etc. While women are smaller than men on average for many body measurements, women are larger than men in some important aspects. For example, women are significantly larger than men in seated hip breadth in all three populations (26 mm larger on average) while at the same time significantly smaller than men for shoulder breadth (54 mm smaller on average). CAESAR also has the advantage of providing 3D models of all subjects. This capacity was also used to provide visual comparison of subjects which is helpful for understanding the differences and deriving solutions.