In an era of increased teacher accountability, teacher preparation programs across the country are faced with increasing pressure to adopt rigorous and high stakes performance-based assessments, such as edTPA, that provide data-based evidence that their candidates are ready to teach upon program completion. Furthermore, in response to new accreditation standards for teacher training programs established by the Council for Accreditation of Educator Preparation, colleges of education are now required to demonstrate enduring and mutually beneficial partnerships with K-12 partners. Given the influence of the K-12 cooperating teacher (CT) on candidate classroom practice, providing professional development (PD) to CTs on edTPA represents a possible means of accomplishing both goals. This study examined the impact of an edTPA PD workshop designed specifically for CTs on CT practice and candidate edTPA scores. Results suggest that candidates placed with CTs who have received edTPA PD can benefit from increased CT knowledge about the edTPA assessment.