The major objective of the present study is to investigate the effectiveness of using Richard Paul‘s ―Elements and Standards of Reasoning (E&Ss)‖ on improving the Critical Thinking skills as well as writing skills of EFL Saudi students. Students were identified as high, mid and low-level students. The progress of each group was measured through a progressive series of rubric assessments of their writing, examining five key areas important in rhetorical composition: clarity of writing, analysis of author‘s argument, use of supporting information, organization, and grammar and syntax. Through the introduction of this focused Critical Thinking training, student composition improved in all of the five key areas, among all the groups.