Educational reformers have argued that universities and the schools they serve must work as partners in teacher education so as to tighten linkages between theory and practice. Such partnerships ultimately aim to achieve "simultaneous renewal" wherein each institution participates equitably in a "mutually beneficial relationship." However, because partnerships are commonly initiated and evaluated by universities rather than schools, research on the effectiveness of these efforts in meeting partnership goals has typically focused on benefits to university students rather than to the host schools. Partnership models assume that schools benefit, if indirectly, because partnership-based programs will produce teachers whose preparation is more closely aligned with schools' needs. But do school personnel perceive these and other benefits? And if so, do they perceive such benefits as a fair trade for the challenging work that is required for genuine institutional collaboration? Voices of school staff are largely silent in this regard. To address this research gap, the authors attempt to gain greater insight into an under-examined perspective by conducting observations, surveying teachers, and interviewing the principal at one urban high school about their experiences collaborating with a university. The larger context of this study is a partnership that joins a university with secondary city schools in the goal of preparing aspiring teachers who will thrive in urban classrooms. Recently, the university began locating teacher education courses on neighboring middle and high school campuses so that pre-service teachers might benefit from immediate and direct contact with life in urban schools, with the further expectation that this effect would be enhanced when the courses were co-instructed by host schoolteachers and university professors. This partnership model assumes that host schools will develop capacity alongside the aspiring teachers enrolled in site-based university courses, yet there has been little examination of benefits host schools derive from such collaborations or how a site-based co-instruction model might facilitate such benefits. This study addresses two questions: (1) What collaborative processes, benefits, and challenges are perceived by school stakeholders as being associated with a site-based co-instruction partnership model?; and (2) What do these findings suggest about relationships among process, context, and perceived outcomes in the site-based co-instruction model? (Contains 3 notes.)