Clinicians and training programs strive to implement evidencebased practices and manualized treatments with fidelity. However, the constraints of a local setting may limit the extent to which this is possible. In the current study, an adapted model of an evidencebased social-emotional learning small group curriculum, the Incredible Years Children's Small Group Training Series (WebsterStratton, 2004), was implemented and evaluated in an elementary school setting. Results of the study demonstrated statistically significant decreases in problem behaviors and intensity of problem behaviors, as rated by teachers. Teachers also reported improvement in classroom behavior, emotion regulation, problemsolving, and friendship skills, as well as a high overall level of satisfaction with the intervention itself. Discussion of the results includes a review of the strengths and limitations associated with outcome research in a naturalistic setting, suggestions to consider when adapting evidencebased programs, and recommendations for future research. [ABSTRACT FROM AUTHOR]; Copyright of Psychology in the Schools is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)