The purpose of this study was to explore the effects of 2 modes of instruction (Short-block versus Long-block) on Iranian EFL learners' reading motivation and reading attitude. For this study, 60 pre-intermediate level students who were studying in an English language institute in Ahvaz were selected. They took part in a homogeneity test (OQPT) to determine their homogeneity level. Then they were randomly divided into two groups, 30 learners each included, namely short-block instruction group and long-block instruction group. Then the two groups were given a reading motivation questionnaire and reading attitude survey as the pre-test before treatment to determine the participants’ reading motivation and reading attitude. During the eleven-session treatment, the long-block group was taught the reading comprehension in an intensive 75-minute session, while the short-block group was taught in three short sessions (twenty-five- minute session). After the treatment sessions, the participants were given a reading motivation questionnaire and reading attitude survey as a posttest. Data were analyzed through descriptive statistics and one-samples t-tests and the findings showed a significant difference between the groups. The short-block group outperformed the other groups in both reading motivation and reading attitude post-test. Implications of this study could be a hint for both EFL teachers and learners that teaching through short-block instruction is more effective than long-block instruction in teaching reading comprehension.