The aim of this paper is to examine the role of composing process and knowledge about coherence/cohesion in French foreign language writing skill. Research sample consists of 35 Turkish students studying French language teaching at a Turkish university. The participants were first given a test containing of three parts in order to determine their level of knowledge about the rules of coherence-cohesion; then, they were asked to write an argumentative essay to see how good they were at writing. Right after the completion of essays, students were administered a 29-item questionnaire concerning the use of composing process. Findings have revealed the following conclusions: 1-Turkish FFL students who know the rules of coherence/cohesion have better writing skills; 2-The participants with better writing skills are those who can employ the composing process; 3-Knowing only the rules of coherence/cohesion or only employing the composing process is not enough to have advanced writing skills in French: both are necessary to be successful. According to the results, it is possible to suggest that rules of coherence/cohesion and composing process be incorporated into the syllabus of writing course and writing course be heavily based on these two topics. Teachers should explicitly teach the process and rules.