In the United States, the federal Individuals with Disabilities Education Act (IDEA) specifies that students with disabilities should be educated in the "least restrictive environment," yet little is known about how successfully schools have been able to apply appropriate supports, practices and resources so that all students benefit from inclusion. Using a quasi-experimental method and a longitudinal data-set provided by the Florida Department of Education that spans an eight-year panel from 2001 through 2009, this paper analyses the relationship between the density and diversity of peers with special educational needs and general education students' absence rates in grades three through eight. Results show that a one standard deviation increase in the measure of special education peers is associated with an increase in general education students' absences of 0.03 to 0.43 more days per year, depending on the empirical specification chosen. This represents as much as a five percent increase in the average student's annual absences. Implications are discussed.