Abstract: The present study aimed at investigating whether testing frequency had anyeffect on language achievement of Iranian EFL learners at pre-intermediate level. Since random assignment was not possible, the nonequivalent group, pretest-posttest design was employed to study three classes of pre-intermediate learners as control and experimental groups. The results of the one-way analysis of variance (ANOVA) from the gain scores of participants indicated a significant difference among the three groups. Additionally, the result of Scheffé’s post hoc test showed that those participants who received weekly tests outperformed those who received biweekly tests.