The study aims to identify the effect of using brainstorming method in the teaching of English grammar; to improve the level of sixth grade students in English grammar at public schools in Jordan. The study population consisted of all sixth grade students of both sexes. The sample of the study was chosen in the random stratified manner, represented in four schools: two for males and two for females, which were divided into two groups (experimental and control). The results showed that there were significant differences at the level of (a = 0.05) in the achievement test in the English grammar, in favor of the experimental group. The results also showed significant differences between males and females in the achievement test in favor of the females. One of the most prominent recommendations was to refer to those concerned with educational guidance, and school administrations to give priority to the issue of the weakness of students in English grammar by focusing on the use of modern methods of teaching, including the method of brainstorming. This study deals with a vital subject concerns those interested in the educational process, especially in the field of teaching English, where the study sheds light on the method of brainstorming and how to benefit from it to narrow the gap resulting from traditional practices in the teaching of English grammar, in order to reach objective results that reflect the pedagogical and educational reality regarding the level of students' achievement in the English grammar.