The purpose of this research is to develop the narrative writing skills of the EFL advanced learners through a unit plan strategy. Participants of the study included 30 students who were randomly chosen and divided into two groups: treatment (N=15) and non-treatment (N=15). The treatment group received instruction using the unit plan strategy with its four stages: identifying the story elements, writing quick drafts, writing long drafts, and final copies. These four stages of the strategy included ten steps. On the other hand, non-treatment group received their regular instruction. The instruments of the study were; an achievement narrative writing test and a scoring writing rubric modified by the researcher to assess the language learners' narrative writing skills. Data were collected and t-test was used for the statistical analysis. Results indicated that there was a statistically significant difference between the mean scores of the treatment and non-treatment groups in the achievement narrative writing post- test favoring the treatment group. It was concluded that the present research provided evidence for the effect of the unit plan strategy on developing the EFL advanced learners' narrative writing skills