This study aims to examine the effectiveness of using sheltered instruction for developing EFL writing skills among preparatory official language school pupils. The participants of the present study consisted of two groups (experimental and control groups) of first year preparatory school pupils at EL Khosous Official Language School, El Khosous Educational Administration, Qaliupia Governement, Egypt during the first term of the academic year 2023/2024 includes 35 of each group. The researcher prepared EFL writing checklist. The teacher used pre-post EFL writing skills and quantitative and qualitative research method for collecting data. the researcher follows experimental method.The pupils' scores improved on the EFL writing test. Hence, it is possible to develop the EFL writing skills at other educational stages. The results revealed that there was a statistical significant difference at using sheltered instruction between EFL writing pre-posttest for developing EFL writing skills among first year pupils at preparatory official language school . th.