Idioms occur frequently in classroom language. Students with literacy or language weaknesses are often challenged by idioms; therefore, the failure to comprehend idioms can impact academic performance. Four 7th-grade female students (mean age: 12 years, 6 months) participated in a multiple baseline single subject study during their general education intensive reading class. Three sets of idioms were taught to examine the effects of classwide peer tutoring (CWPT) intervention on idiom comprehension. Following implementation of CWPT, comprehension of most idiomatic phrases increased and remained largely stable as indicated through visual analysis. Teaching idioms with CWPT was flexible, effective, and time-efficient in a general education classroom setting. Speech language pathologists collaborating with educators should provide evidence-based interventions as guided by educational standards and curriculum. Response to intervention provides a framework to implement a classroom intervention for all students to facilitate idiom understanding. (Contains 5 figures and 3 tables.)