Classrooms are unique and complex work settings in which teachers and students both participate in and contribute to classroom processes. This article describes the measurement phase of a study that examined the social ecology of urban classrooms. Informed by the dimensions and items of an established measure of organizational climate, we designed the Student Climate Survey (n = 53 items) to assess student psychological climate in third through eighth grades. We administered the survey to 621 students at three time points within one school year in 69 classrooms within eight urban schools. A multidimensional item response theory (IRT) analysis based on a full-information item bifactor model revealed 18 items that loaded on a primary factor and demonstrated good criterion and predictive validity. Opportunities for the Student Climate Survey to advance our contextual understanding of urban classrooms and inform intervention are discussed.