The purpose of this study was to determine whether the type of questions used to assess childhood sexual abuse (CSA) introduces systematic bias into estimations of the magnitude of the association between CSA and alcohol use disorders (AUDs). Method: The Semi-Structured Assessment for the Genetics of Alcoholism was administered by telephone to 3,787 female twins ages 18-29 years (14.6% African American, 85.4% White). Interviews included questions regarding sexual abuse experiences described in behavioral terms and a standard trauma checklist (in a separate section) with the items "rape" and "sexual molestation," with defi nitions provided in respondent booklets. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnoses of alcohol abuse and dependence, parental history of alcohol-related problems, and psychiatric conditions associated with AUDs were also assessed. Results: The majority of women who endorsed one question type also endorsed the other type. Rates of psychiatric risk factors for AUDs did not vary by pattern of CSA question endorsement. Separate Cox proportional hazards regression analyses using CSA variables derived from behavioral questions (hazard ratio [HR] = 1.67, 95% CI [1.27, 2.19]) and checklist items (HR = 1.41, 95% CI [1.08, 1.84]) each revealed elevated risk for AUDs associated with CSA, and HRs did not differ significantly across models. However, a Cox proportional hazards regression analysis predicting AUD from the pattern of CSA question endorsements revealed a significantly higher risk for AUDs among women who endorsed only behavioral questions (HR = 3.26, 95% CI [1.72, 6.21]) than for all other groups. Conclusions: Findings underscore the importance of querying CSA in studies of alcohol-related problems and highlight some of the limitations of assessment methods that can be integrated into studies covering a wide range of psychosocial domains.