This study reports the results of a peer-mediated intervention, total class peer tutoring, on the academic performance of six urban students at risk for reading failure. A multiple baseline design across subjects was used to evaluate the effects of this intervention. The results showed that five of the six students significantly increased their sight-word acquisition and maintenance. All target students' reading fluency and comprehension scores on the standardized "Dynamic Indicators of Basic Early Literacy Skills" (DIBELS) Oral Reading Fluency (DORF) passages were higher during intervention than at baseline. Greater fluency gains were shown on constructed paragraphs that included the tutoring sight words. More modest fluency and comprehension gains were found in DORF passages that did not contain words taught in the intervention. Social validity measures taken from teachers, parents, and students revealed positive evaluations of the intervention. Limitations, future directions in research, and practical implications are discussed.