This study examined the effectiveness and efficiency of combining classwide peer tutoring (CWPT) and constant time delay (CTD) on the academic performance of 3 students with learning disabilities (LD) and 15 students without LD enrolled in an inclusive sixth-grade language arts class. Treatment integrity checklists were used to measure the extent to which the tutors with LD used the constant time delay procedure correctly. A multiple-probe design across behaviors replicated across students was used to examine the effectiveness of the CTD peer tutoring procedures. The results indicated that students with LD reliably implemented the CTD peer tutoring procedures with a high degree of treatment integrity. When implemented by students without LD, the procedures were effective and efficient for teaching targeted vocabulary words to students with LD. Similarly, students without LD mastered the targeted vocabulary words when tutored by peers with LD and by peers without LD using the CTD peer tutoring procedures. Additionally, students with LD and without LD maintained the targeted vocabulary words over time, generalized the words across context, and generalized the CTD peer tutoring procedures across content. Finally, measures of social validity indicate that students and teachers involved in this study were satisfied with the CTD peer tutoring procedures.