The current study aimed to investigate The Effectiveness of the Big Six Model in Developing EFL Critical Reading Skills for Secondary Stage Students. The participants of the study were 60   first year secondary school students at a public secondary school in Giza governorate. They were  randomly selected and divided into an experimental group (n=30) and a control group (n=30).The quasi- experimental pre-test and posttest design was used. The Study employed a pre-post critical reading test and analytic rubric. The experiment lasted for two months during which students of the experimental group received training through the proposed treatment based on the Big6 Model while those of the control group received regular instruction. The study results showed evidence that there was a statistically significant difference at 0.05 level between the mean scores of the control and the experimental groups on the post administration of the test, in favor of the experimental group in overall critical reading skills as well as in each critical reading skill separately. It was concluded that  using the Big6 Model was effective in developing the required critical reading skills among the experimental group students. Consequently, it was recommended that the Big6 model should employed in teaching critical reading skills the primary school students and investigating its effect on developing EFL speaking skills and critical thinking skills.