This study aimed at investigating the effect of literature circles on developing reading comprehension and vocabulary acquisition of second year official language preparatory school students. This study adopted the quasi experimental design. It was conducted on 60 students. These participants were selected at random from Sebrbai Official Language School In El- Gharbia Governorate, in the school year 2021/2022.The participants were divided into experimental and control groups, 30 students in each. The experimental group received training through literature circles treatment. On the other hand; the control group received regular instruction. The scores of the students on the reading comprehension and vocabulary acquisition pre and post tests were statistically analyzed by applying the paired sample t –test to compare the means of the pre and post tests of the experimental group. In addition, the independent two samples t –test was used to compare the mean scores of the experimental and control groups on the reading comprehension post test and vocabulary acquisition post test. Study results indicated that there were significant improvements in favor of the experimental group concerning overall reading comprehension and the three levels of meaning; literal meaning, inferential meaning, and evaluative meaning. Relevant interpretation, recommendations, and suggestions were offered.