Focus on Form (FonF) instruction places dual emphasis on meaningful interaction and overt reference to problematic or more complex forms in L2 classes. One way to draw attention to such forms is through incidental preemptive FonF. As an attempt to expand the scope of teacher-initiated preemptive FonF, the present quasi-experimental study explored the applicability of planned preemptive FonF in writing classes. Specifically, it investigated the relative impacts of indirect comprehensive written corrective feedback (WCF) with and without planned preemptive FonF on two groups of advanced Iranian EFL learners' essay writing ability. The control group (N = 18) received delayed reactive FonF (i.e. WCF) following their essay writing practices from their teacher. On the other hand, the experimental group (N = 18) received planned preemptive FonF prior to their writing practices in addition to delayed reactive FonF. The findings based on paired samples t-test and the analysis of covariance (ANCOVA) indicated that the writing performance of both groups improved though at significantly varying rates. When delayed reactive was accompanied with planned preemptive FonF, the learners were able to craft better essays. This study demonstrates that preemptive FonF easily lends itself to be planned in writing courses and calls for employment of both planned and incidental preemptive FonF along with WCF in writing courses.