Professional Development Schools (PDSs) are collaborative ventures between schools and teacher training institutions. We identify the characteristics of a school that lead to successful PDS collaboration, relating them to Teitel's model (2003) that merges the principal standards of collaboration with the stages necessary for developing a PDS. We then describe an external evaluation of a PDS in action in Israel, noting that it took several years to achieve some of the objectives; others have still not been met. Finally, we describe the school's characteristics that contributed to its success as a PDS.