This article explores central elements that facilitate successful mathematics professional development in urban secondary schools through a case study of one long-term effort. The following research question guided this study: How can schools structure professional development that supports teacher learning and addresses the complex realities of urban practice? This study took place in an urban school (The City School [pseudonymn]: 1,500 students, grades 6-12) located in a large city. Most of the student body was minority (99.8% African American) and considered underprivileged (according to government free and reduced lunch records). Participants included three high school mathematics teachers (female, African American), all of whom had undergraduate degrees in mathematics but did not yet hold teaching credentials. Data were collected throughout the 2004-2005 school year. Data sources included: transcripts of audio-taped instructional sessions (30) and informal meetings (10), researcher field notes of all sessions and meetings, transcribed formal interviews (3) with participants, participant journal entries and course assignments (e.g., content exams, problem sets, narrative refections, lesson design), initial surveys and end of program evaluations, observation field notes of participants' practice (five per participant), e-mail correspondences, and researcher journals. They conducted semi-structured interviews (30-45 minutes) with participants at the beginning, middle, and end of the project. This work supports the notion that teacher educators must understand more about teachers' needs, particularly in failing schools, before engaging in professional development. This study promotes the idea that teachers involved in professional development situations and/or research projects need to view the facilitators as human beings who care, as opposed to merely outsiders telling them what to do and how to behave. Based on the authors' experiences working in this effort, they have found the interactions within a given structure to be just as important as the existence of the structures themselves. As a result, they urge others to consider and systematically study the complex component that context, particularly the relationships embedded within a professional development community, plays in teacher learning and change in practice.