The purpose of this study was to investigate the effects of active learning on foreign language self-concept and reading comprehension achievement. This research was carried out through an experimental design with experimental and control groups. In the Spring Term of 2005-2006 Academic Year, 182 male college students formed the experiment and the control groups which were all randomly chosen. Active learning techniques were applied to experiment groups for 13 weeks while the control groups were educated through traditional methods in teaching English. The data of the research were gathered by the Foreign Language Self-Concept Scale which is developed by the researcher and a reading comprehension placement test. The results demonstrated that the researcher-mediated learning environment, i.e. the group engaged in active learning techniques, was successful in enhancing reading comprehension achievement. On the other hand, the effect of active learning on foreign language self-concept was found to be insignificant. Furthermore, there is no significant correlation between foreign language self-concept and reading comprehension scores according to the types of high schools the students have graduated from.