Learning the writing skill is a challenging task for second or foreign language learners. This difficulty stems from the fact that students required multiple skills and knowledge while writing. They need, for example, enough vocabulary inventory, grammar knowledge, and other discourse strategies to organize the text. Students are also in need for background knowledge about the subject matter of the writing task, so they generate their ideas accordingly. To achieve all these targets and to meet the challenges, a need for an approach that meets the requirement of the written task and enhances the students' abilities and linguistic background is a must. The aim of this research is to investigate two of the available approaches; namely, the TBL approach and the conventional 3Ps model, to improve Saudi EFL students' writing skill in Jouf university. The focus is on finding out the effect of the two approaches, the differences between them, and what are the aspects of improvement that TBL approach can achieve. The data were collected experimentally through writing pretest and posttest after students received training using the two approaches for 6 weeks. The findings revealed that using TBL approach is significantly effective in learning writing skill. It was also found that TBL approach is more effective than the conventional model. Furthermore, findings demonstrated that employing TBL approach on teaching Saudi EFL students' writing skills improved five writing sub-skills including organization, content, mechanism, grammar, and vocabulary with the organization and content the most improved areas.