The purpose of this study was to examine factors that may be associated with variation in social workers' perceptions of effectiveness, perceptions of acceptability, and use of psychosocial evidence-based practices (EBPs) for the treatment of substance use disorders (SUD) in comparison to other SUD counselors who are non-social workers. A national sample of 1,140 counselors in private SUD treatment settings completed a mailed survey. Overall, counselors perceive both motivational interviewing (MI) and contingency management (CM) to be effective and acceptable interventions, with MI perceived to be both more effective and more acceptable than CM. The results of this study also shed light on the factors associated with perceptions of effectiveness and acceptability of MI and CM. The results of this study underscore the importance of exposure to EBPs in the development of positive attitudes toward and use of EBPs. In particular, professional networks are an important route to introduce social workers to EBPs, as is professional training on specific EBPs. Efforts to increase the uptake of evidence-based SUD interventions should not be limited to dissemination of information regarding effectiveness; rather, efforts should also be expended to expose social workers to EBPs.