The precise assessment of childhood adversity is crucial for understanding the impact of aversive events on mental and physical development. However, the plethora of assessment tools currently used in the literature with unknown overlap in childhood adversity types covered hamper comparability and cumulative knowledge generation. In this study, we conducted two separate item-level content analyses of in total 35 questionnaires aiming to assess childhood adversity. These include 13 questionnaires that were recently recommended based on strong psychometric properties as well as additional 25 questionnaires that were identified through a systematic literature search. The latter provides important insights into the actual use of childhood adversity questionnaires in a specific, exemplary research field (i.e., the association between childhood adversity and threat and reward learning). Of note, only 3 of the recommended questionnaires were employed in this research field. Both item-wise content analysis illustrate substantial heterogeneity in the adversity types assessed across these questionnaires and hence highlight limited overlap in content (i.e., adversity types) covered by different questionnaires. Furthermore, we observed considerable differences in structural properties across all included questionnaires such as the number of items, age ranges assessed as well as the specific response formats (e.g., binary vs. continuous assessments, self vs. caregiver). We discuss implications for the interpretation, comparability and integration of the results from the existing literature and derive specific recommendations for future research. In sum, the substantial heterogeneity in the assessment and operationalization of childhood adversity emphasizes the urgent need for theoretical and methodological solutions to promote comparability, replicability of childhood adversity assessment and foster cumulative knowledge generation in research on the association of childhood adversity and physical as well as psychological health.