We conducted a systematic literature review examining the participant characteristics of studies of students with emotional disturbance (ED) with the purpose of better understanding potential similarities and differences between students with ED in research and the population of students with ED. Results indicate (a) participants with reported demographics were predominantly White or Black/African American and male; (b) participants in research samples were significantly different from the national population on gender, age, and race across study designs; (c) the research samples included significantly more White and Black/African American participants and fewer from other minority racial groups compared with the national population; (d) male participants were overrepresented and female underrepresented in studies generally, but the pattern was reversed in researcher-recruit samples; and (e) young children ages 3 to 5 years old were severely underrepresented in the research sample. We discuss the implications of this review and future directions for research.