This study investigated the convergent validity between two classical measures of childhood sexual abuse (CSA): the Russell Sexual Abuse Interview Schedule (Russell, 1983) and Finkelhor Survey of Childhood Experiences (Finkelhor, 1979). One hundred sixty eight participants were recruited from a Midwestern university. In addition to the two CSA measures, the following measures were also compared: a subject demographic information form, the Trauma Symptom Checklist-40 (Briere and Runtz, 1989), the Simple Screening Instrument for Substance Abuse (Center for Substance Abuse Treatment, 1994), and Rotter's Internal and External Locus of Control Scale (Rotter, 1966). This study provided support for convergent validity between the Finkelhor and the Russell. The majority of participants who reported CSA on the Finkelhor also reported CSA on the Russell, with more participants reporting CSA on the Russell. Although participants' responses on the Finkelhor were positively correlated with their responses on the Russell with respect to severity of the CSA, most participants did not receive the same rating for severity level on both measures. More participants endorsed experiencing CSA by a family member on the Russell than on the Finkelhor. There were significant positive relationships between presence, severity, and duration of abuse (as measured by the Finkelhor for some participants) and scores on the TSC-40, but fewer for the Russell. There were no significant relationships between identifying a family member as the perpetrator of the CSA on the Russell and Finkelhor and scores on the TSC-40 and scores for substance abuse. There were also no significant relationships between presence of CSA as measured by the Finkelhor and Russell and scores for substance abuse. The results of this study found support for discriminant validity for both CSA measures, as scores for neither measure correlated with scores on Rotter's I-E Scale. The results of this study suggest that more research needs to focus on developing consensus on the definition of CSA and on determining how to measure frequency, severity, and duration of CSA accurately. Research on how to measure the characteristics of CSA can yield important information about the relationships between these characteristics and negative outcomes, such as substance abuse, which can be used to inform treatment.