Usability or safety issues result when products are not designed with the end user in mind. As the majority of engineering degree recipients are men, products designed by engineers are often inadequate for women users. One example of this is the higher fatality rate for women in car accidents when compared to men, due to safety systems in cars being designed by and for men. The mechanical design field lacks deep investigation into why and how gender bias manifests along the design process to ultimately result in a problematic product, despite the existence of many gender-biased products with proven consequences; although, other fields, such as medical, human resources, and journalism, have taken concrete steps to identify and address the causes and effects of gender bias. The goal of this work is to understand how gender bias influences the early stages of user-centered design. To fulfill this primary goal, the proposed research has been divided into three parts, with each one fulfilling a more specific research objective. Part I will explore usage of makerspaces, a common site for gender inequity in engineering, through observation and ethnographic interviews with makerspace users. Makerspaces have been identified as an environment where gender impacts user experience, both because makerspaces are typically men-dominated and because different areas of makerspaces have strong gender stereotypes attached. Findings from Part I will be used to develop study materials for the following studies. Part II will examine how a user’s gender and the stereotyping of a design problem influences the designer’s interpretation of customer problems and needs in order to explore how gender bias manifests in the problem definition phase of the design process. Finally, Part III will build on the previous studies to develop and test bias mitigation interventions for designers. This work is expected to contribute significantly to the design field by providing 1) an exploration into the concrete effects of gender bias in the design process and 2) a validated process for reducing harmful effects of designers’ gender bias.