Background: First responders (e.g., emergency medical technicians, firefighters) may be at higher suicide risk than the general population due to frequent exposure to suicidal behaviors of others. Aims: We aimed to confirm the factor structure, scale reliability, and convergent validity of a new measure of suicidal exposure, the Suicidal Behaviors Exposure Scale, in first responders. Method: Using a cross-sectional web-based survey, we recruited 862 participants (81.3% male, mean age = 40.23, SD = 11.88) from a national database and southeastern state-based organization of first responders. Results: Confirmatory factor analysis resulted in a generally poor fit for the three-factor structure (exposure to suicidal communication, indirect exposure to suicide attempts/deaths, direct exposure to suicide attempts/deaths). However, good scale reliability and convergent validity were demonstrated. Limitations: The cross-sectional design, a convenience sample, and the low percentage of women comprise the limitations of this study. Conclusion: The Suicidal Behavior Exposure Scale requires additional development and validation before use in a first-responder sample. Future work should also examine other aspects of reliability and validity, namely, measurement invariance across groups and time.