Background Although classroom quality is an important consideration, few recent research studies have examined the process and structural quality in publicly funded early childhood education (ECE) and inclusive ECE classrooms. This study provides an important contribution to the literature by comparing two conceptualizations of quality in classrooms serving children from low-income households and those with disabilities. Objectives (1) To characterize and to determine differences with regard to process and structural quality in publicly funded ECE and inclusive ECE classrooms, and (2) to examine whether and to what extent the process quality varied when controlling for structural quality and classroom income/race variables. Method One hundred and sixty four classrooms (85 ECE, 79 inclusive) that were enrolled in two large-scale intervention studies examining a book-reading program were included in the present study. The Classroom Assessment Scoring System (CLASS; Pianta et al. in Classroom assessment scoring system, Paul H. Brookes, Baltimore, 2008) and three detailed questionnaires were used to quantify process and structural quality, respectively. Results Results revealed quantitative differences in process quality, specifically in the emotional support dimension of negative climate as well as all dimensions of instructional support, between the two settings. In addition, teachers' education was a significant predictor of process quality, and publicly funded ECE classrooms scored over two points higher on the instructional support domain of the CLASS when controlling for other structural quality measures and income and race. Conclusions Our findings have implications for best practice guidelines and policies, particularly for classroom environments serving children with disabilities, which are discussed. (author abstract)