This study investigates the effects of pre-task planning and online planning on L2 writing production (complexity, accuracy, fluency, and lexical variety). Seventy-eight intermediate EFL learners were randomly divided into three groups (n1/3 26): pre-task planning, online planning, and no planning. Participants were required to write a description elicited through a pictorial task. Analysis of the descriptions and the results of a series of one-way ANOVA showed that the participants who completed the task under the pre-task planning condition composed more fluent texts. However, those who conducted the task under the no planning condition wrote more lexically varied texts. In addition, the participants who completed the task under the online planning condition outperformed those who worked with the task under the pre-task planning condition in the case of lexical variety. This study proposes the trade-off effect between fluency and lexical variety. The findings also reveal that choosing suitable task-based implementational conditions can help L2 writers improve the complexity, accuracy, fluency, and lexical variety of their textual products. Finally, the implementational conditions for pre-task and online planning should be equally available for L2 writers if they want to present their actual output.