In applications that require space-suited crewmembers to traverse rough terrain, boot fit and mobility are of critical importance to the crewmember's overall performance capabilities. Current extravehicular activity (EVA) boot designs were developed for micro-gravity applications, and as such, incorporate only minimal mobility features. Recently three advanced space suit boot designs were evaluated at the National Aeronautics and Space Administration Johnson Space Center (NASA/JSC). The three designs included: 1) a modified Space Shuttle suit (Extravehicular Mobility Unit or EMU) boot, 2) the Modified Experiment Boot designed and fabricated by RD & PE Zvezda JSC, and 3) a boot designed and fabricated by the David Clark Company. Descriptions of each configuration and rationale for each boot design are presented. The boots were evaluated by suited test subjects in a three test series: 1) isolated boot joint mobility testing, 2) treadmill walking tests under a partial gravity condition, and 3) exercises performed on the JSC Extravehicular Activity (EVA) Remote Field Demonstration Test Site. The test protocols are briefly described, the test data is presented, and the test results are discussed. Further, advantages and disadvantages of the various boot design features are discussed. Along with other key findings, this study concluded that boot fit and comfort contribute significantly to the perceived boot performance.