Biological motion research is an increasingly active field, with a great potential to contribute to a wide range of applications, such as behavioral monitoring/motion detection in surveillance situations, intention inference in social interactions, and diagnostic tools in autism research. In recent years, a large amount of motion capture data has become freely available online, potentially providing rich stimulus sets for biological motion research. However, there currently does not exist an easy-to-use tool to extract, present and manipulate motion capture data in the MATLAB environment, which many researchers use to program their experiments. We have developed the Biomotion Toolbox, which allows researchers to import motion capture data in a variety of formats, to display actions using Psychtoolbox 3, and to manipulate action displays in specific ways (e.g., inversion, three-dimensional rotation, spatial scrambling, phase-scrambling, and limited lifetime). The toolbox was designed to allow researchers with a minimal level of MATLAB programming skills to code experiments using biological motion stimuli.