This article presents findings from an exploratory empirical study of teaching residents' opportunities and learning within the overlapping contexts of English as a Second Language (ESL)/special education classrooms and high-need urban schools. Utilizing documentation from the first year of a teacher residency program, our findings illustrate the central role that mentor teachers play in determining the kinds of opportunities afforded to teaching residents and the ways in which factors unique to these clinical contexts shape learning. Implications center on the preparation of mentor teachers and the work of teacher education programs in the US.