The present study aims to investigate the effect of Multiple-Intelligence-Based Instruction (MI) on learning process and attitude towards General English course among students of Islamic Azad University of Kermanshah in the second semester of the educational year 2010-2011. 61 male and female students in two different General English classes were selected using random cluster sampling. The experimental group consisted of 32 students, and the control group included 29 students. A quasi-experimental research method with a pretest and posttest design was used. The experimental group was taught in accordance with the theory of MI and the control group was instructed using the classical method of teaching General English. The course duration was eight weeks. A 30-item researcher-made survey was used to determine the effectiveness of Multiple-Intelligence-Based Instruction compared with the classical method. Besides, a 15-item questionnaire was used to assess the learners’ attitude towards General English course. The multivariate analysis of covariance (ANCOVA) and the independent sample t-test were used to analyze the statistical data.  The results of the study showed that there was a significant difference in the level of General English learning progress between experimental and control groups. In other words, the students taught applying MI theory exceeded those taught using classical methods both in general and separate levels of learning English (vocabulary, reading comprehension, and grammar). The results also indicated that the attitude of experimental group students towards learning English improved significantly after the test course.