Objective: This study focused on identifying any possible relationship between symmetrical (S) and asymmetrical (AS) scaffolding and writing ability of Iranian students of English as a Foreign Language (EFL). The study also examined the influence of gender as a moderating variable on the writing ability of students when taught with symmetrical vs. asymmetrical scaffolding. Methodology: After administering a Pre-test, 52 homogeneous intermediate students were selected, and they were divided into two experimental groups. Results: The experimental group (A) received instruction according to S strategy whereas the experimental group (B) was instructed via the AS strategy. A Post-test was administered, and its results were analyzed through Two-way ANOVA. Conclusion: The results indicated that S scaffolding and AS scaffolding have significant effect on learners' performance in Writing ability. The findings also showed that gender did not modify the relationship between scaffolding and students` writing ability.
