Moral injury (MI) is defined as the profound psychological distress experienced in response to perpetrating, failing to prevent, or witnessing acts that transgress personal moral standards or values. Given the elevated risk of adverse mental health outcomes in response to exposure to morally injurious experiences in military members, it is critical to implement valid and reliable measures of MI in military populations. We evaluated the reliability, convergent, and discriminant validity, as well as the factor structure of the commonly used Moral Injury Events Scale (MIES) across two separate active duty and released Canadian Armed Forces samples. In Study 1, convergent and discriminant validity were demonstrated through correlations between MIES scores and depression, anxiety, posttraumatic stress disorder, anger, adverse childhood experiences, and combat experiences. Across studies, internal consistency reliability was high. However, dimensionality of the MIES remained unclear, and model fit was poor across active and released Canadian Armed Forces samples. Practical and theoretical implications are discussed.