Normal human communication manifests itself mostly either in written or spoken form. Examination of speech and writing processes enables psycholinguists to peek into the way people plan their language production. This article aimed to examine how EFL learners plan their writing activities. To this end, two groups of High proficiency (HPG) and Low proficiency (LPG) of 16 EFL students were asked to write an argumentative essay on the given topic. Based on the data obtained from their think-aloud protocols, retrospective interviews, and the comparisons of the two groups’ performance, it was found that both groups approached the writing task in a linear progression of three stages of Formulation, Execution, andMonitoring. However, there were differences in the ways the two groups planned their writing productions.