This study identified facilitators of and barriers to collaboration in Professional Development Schools (PDSs). Researchers conducted a meta-ethnography, which synthesized qualitative research and attempted to analyze processes and outcomes across many studies. Case studies of the collaboration process in PDSs were collected and screened, then themes were coded and interpreted. A literature search yielded 66 case studies. After screening, 20 case studies remained. Each case study was analyzed in terms of geographic region, type of partnership, urban or suburban setting, number of years in the partnership, and authors. Facilitators of the collaboration process that were interpreted from the 20 case studies were: obtaining needed resources from outside organizations; administrative support, taking time to establish a shared vision; and the feeling that PDSs increase professional development. Barriers to collaboration included time, lack of rewards, the change process, district mandates, and space. The paper presents six recommendations to practitioners, schools, and teacher education institutions for beginning and sustaining a PDS. (Contains 56 references.) (SM)