This study examined the effects of testing accommodations on students' test performances and reactions to the use of testing accommodations. Participants (N = 170) were fourth- and eighth-grade students, with and without disabilities. All students were administered, with and without accommodations, equivalent forms of widely used math and reading tests. Students completed a questionnaire to summarize their reactions to the use of accommodations. The findings indicated testing accommodations overall had a positive impact on students' individual reading and math scores. Furthermore, testing accommodations had a differential positive effect on reading scores for students with disabilities compared to students without disabilities. The relationship between students' perceptions of testing accommodations and the effects of testing accommodations on their test performances was not significant, although most students had positive perceptions of testing accommodations. Students perceived the provision of accommodations as fair for students without disabilities and more fair for students with disabilities. These findings are interpreted within a validity framework and contribute to a greater understanding of testing accommodations by integrating information concerning effects on scores and consequential effects on test-takers. (Contains 7 tables.)