The importance of meaning-based teaching of the writing skill as an end in itself has mostly overlooked due to the common traditional grammar-based approaches used in writing instructions within the English as a foreign language (EFL) context. Therefore, this study aimed to examine the effects of collaborative meaning-focused and grammar-focused pre-writing task on complexity, accuracy, and fluency in EFL learners' written products. To this end, 113 Iranian EFL learners were selected. The learners were randomly assigned to two different experimental groups, namely grammar-focused group and meaning-focused group, and one control group. After doing a writing task as the pretest, the participants in the two experimental groups received task manipulations during a fifteen-minute prewriting phase for seven sessions. Afterwards, all the participants attended a final posttest of writing. The findings revealed significant effects of the meaning-focused pre-writing tasks on the participants' writing fluency, and the significant effects of the grammar-focused pre-writing tasks on the participants' writing accuracy. The results also showed that the experimental groups outperformed the control group in terms of complexity. However, there were no significant differences between the two experimental groups. The implications of the findings are also discussed.