This article describes the development and validation of the 40-item Theoretical Orientation Scale for Clinicians (TOSCsF), an instrument designed to (a) operationalize attitudes towards the principles of solution-focused brief therapy (SFBT), and (b) assess clinicians' endorsement of this therapeutic approach. Participants (N=284) were members of the National Association of Alcoholism and Drug Abuse Counselors (NAADAC) who responded (63%) to a mail questionnaire containing the TOSCsF. Reliability (Cronbach's alpha = .82) and validity of scores on the TOSCsF are examined in light of the detection of an acquiescent response pattern in 40 respondents. A subsequent three-factor structure derived from a principal components analysis (accounting for 28% of the variance) suggests modest, but positive, support for the construct validity of the TOSCsF. Recommendations for further refinement of the instrument are discussed.