The present study aimed at developing some EFL critical writing skills for first year Formal secondary school students through a program based on discourse analysis and scenario assessment. The study adopted the quasi-experimental pre-posttest, experimental /control groups. Participants were first year formal secondary school students. Two groups (30 each) were selected from Omar El Farouk secondary school, Dakahlia governorate, Egypt in the first semester of the academic year 2022-2023. The experimental group was taught through the program for developing their critical writing skills. On the other hand, the control group received regular instruction. Instruments were: questionnaires designed for critical writing skills that was designed and approved by a panel of jury. A critical writing test was designed. By the end of the experiment, the test was post administered to both groups to investigate the effect of the program on developing the experimental group EFL critical writing skills. Findings of the study were statistically treated. It was found out that the experimental group achieved more gains in their EFL critical writing skills than the control one. The results of the study were positive; the hypotheses were accepted .