Expository writing (EW) is crucial for the literacy development of students with intellectual disabilities (ID) in inclusive classrooms. Students with ID, however, struggle with EW due to problems with generating, organizing, and producing text. Similarly, teachers of students with ID face challenges with employing the appropriate instructional method to teach EW to students with ID. The current study, therefore, investigated the effectiveness of combining two instructional methods, namely the Four-Square Writing Method and Sentence Frames, in teaching EW skills to students with ID. Using a single group pretest posttest quasi experimental design, 8 students with mild ID who received their education in inclusive classroom in one of the suburban schools in Egypt participated in the study. Participants were aged between 11 and 12 and were enrolled in grades 5 and 6. An intervention instructional program was implemented to teach EW to participants. Prior to and following the intervention participants' EW was evaluated with regard to paragraph length, structure and coherence. Results showed that the use of both strategies had a positive effect on students' EW. Additionally, students retained their intervention gains after a follow up duration of eight weeks. Implications are discussed in relation to the context of teaching literacy skills to students with ID in Egypt.