Introduction: The Uniformed Services University of the Health Sciences coordinates a 2-week Summer Operational Experience (SOE) during the first year of medical school. The SOE aims to provide students with operational context and enhance familiarity with service-specific operational environments, the services' medical department capabilities, and/or general warfighter skills. One overarching goal of the SOE is to provide an experience that may motivate students to pursue an operational medicine assignment at some point in their military career. However, to date, little evaluation data have been collected regarding the effectiveness of the SOE in encouraging medical students to pursue operational medicine assignments. The purpose of this project was to develop and collect initial validity evidence for a survey instrument designed to assess various aspects of students' attitudes and behavioral intentions to pursue an operational medicine assignment at some point in their military career. Materials and Methods: Using the theory of planned behavior as a framework, we developed a survey that focused on three distinct constructs: attitude, subjective norms, and perceived behavioral control. We followed a systematic, seven-step design process to develop the survey and collect initial validity evidence. Students completed the 20-item survey prior to their operational experience to evaluate their intentions to pursue an operational medicine assignment at some point in their military career. An exploratory factor analysis (EFA) and reliability analysis were performed to examine the internal structure of the instrument. In addition, bivariate correlation and multiple linear regression analyses were used to explore the relationships between the identified factors and students' intentions to pursue operational medicine. Results: Results from the expert reviews and cognitive interviews suggested the instrument was clear and interpretable. We then invited the entire class of 2020 who participated in the SOE (149 students) to take the survey; in total, 122 students (response rate = 82%) completed the entire survey. Findings from the EFA suggested four underlying factors with satisfactory internal consistency reliability, and the regression analysis revealed that three factors statistically significantly predicted students' intentions to pursue operational medicine: Attitude: Personal Growth (b = 0.67, β = 0.42, P < 0.001); Behavioral Control (b = 0.20, β = 0.15, P < 0.05); and Attitude: Career Progression (b = 0.36, β = 0.30, P < 0.001). The factor related to student's perception of the importance that others placed on an operational medicine assignment was not a statistically significant predictor of intention. Conclusions: Findings from this study suggest the developed survey yields scores that can reliably assess students' attitudes, subjective norms, perceived behavioral control, and intentions to pursue operational medicine. Using this survey, course leaders have a tool for evaluating the success of the SOE and identifying potential areas for improvement within the curriculum. More broadly, other educators can use the theoretical framework and instrument design process described here to evaluate students' behavioral intentions in their own contexts.