Practice evaluation is an important component in the implementation of evidence-based practice. Until recently it has been difficult to assess practitioner knowledge in evaluation in the field. This study discusses the development and initial psychometrics of an 8-item scale to assess practitioner competency in evaluation. The Practice Evaluation Knowledge Scale demonstrated excellent internal consistency (α =.925) and validity. Results indicate that this scale shows promise as a valid measure of social work practitioner knowledge of practice evaluation. © Taylor & Francis Group, LLC.