The aim of this study is to investigate the effects of Multiple Intelligences Theory compared to the Traditional Teaching Method on grade 9 students' academic achievement and retention of their knowledge about the topics of Heat, Temperature, Expansion and Compressibility. The study in which pre-post test with control group design was used, was carried out with the 9th grade students in Eskipehir Atatürk Anatolian Vocational, Technical and Industrial Vocational High School. 70 students participated in the applications which were done 2 hours a week during 2 weeks. The pre-test was applied to the students at the first week of the study. One of the classes was determined as Control, and other was chosen as the Experimental Group. The traditional teaching method was applied to the control group while the experimental group was thought by using the theory of Multiple Intelligences. All lessons were carried out by the researcher and the experimental group was explained the Multiple Intelligences Theory for 1 period. At the first step of the study The Prior Knowledge Test was applied in order to identify students' prior-knowledge. The Achievement Test was applied after carrying out the lessons which is prepared according to the lesson plans based on the Traditional Teaching Method and Multiple Intelligences Theory. To determine whether the information learned in a permanent, one month after the same test administered to all students. The data obtained from this study were analyzed through the use of SPSS (Statistical Package for Social Science) 15.0 software. In the evaluation of the hypothesis, analysis of variance One-Sample t-Test was used. The meaningful results were acceptable as 0.05 level. The results of statistical analysis indicated that the teaching activities based on the Multiple Intelligences Theory meaningfully contributed to the students' comprehension of Heat-Temperature, Expansion and Compressibility and retention of their knowledge. It was determined that experimental group students showed more interest to the topics according to the observations during the lessons.