Abstract-The present study was undertaken to explore the effect of blended instruction (face-to-face instruction accompanied with online instruction ) on grammar learning in Iranian EFL learners. To test the null hypothesis, two intanct classes containing eighty sophomore female and male students of English translation at Islamic Azad university of arak branch, iran participated. Pre-test means scores showed insignificant differences between the experimental and control groups in their grammatical knowledge. At the end of treatment period, a post-test (the same as pre-test) was administered in both groups to compare their grammar achievement. Adopting a quasi experimental design, the null hypothesis was rejected. Keywords; grammar, e-learning, EFL, technology