This study investigated students with specific learning disabilities (SLD), serious emotional disturbances (SED), and educable mental retardation (EMR) to determine if class size and class mix influence educational outcomes. A total of 110 students in 12 classrooms were included in the sample, which included classes with waivers (classes out of compliance with Virginia standards) for class size or class mix; waivered classes with SLD, SED, and EMR students; and classes in compliance with Virginia standards (non-waivered classes). Four academic achievement areas and nine affective areas were used as educational outcomes in the quantitative and qualitative research. Results indicated that student achievement is affected by class size; students in single disability classes appeared to have higher reading, math, and social studies achievement than students who were mixed with other disabilities; students in non-waivered classes had better general behavior and were making more progress toward their educational goals than students in waivered classes; student self-concept, motivation level, time on task, educational aspirations, liking of special education classes, and awareness of special education placement were not significantly different in waivered versus non-waivered classes; and teaching methods were not significantly different. (JDD)