The purpose of this paper is to examine the overall effectiveness of the English immersion program of a Korean University. In order to achieve the ultimate purpose of the current project, researchers describe the educational principles and curriculum in detail and provide an overall evaluation of the program. The three-week English immersion program in winter 2008 was designed to help students satisfy their graduation requirement and improve their general English proficiency such as listening, reading and writing abilities, by providing them with an immersion English program. To check if there is any improvement after the program, students' achievement was measured by TOEIC both before and after the program. Students' responses from questionnaires were used to identify their needs and satisfaction toward the program. On the basis of the extensive evaluation of the program, it was found that students' needs are more complicated and a re-setting of the program goal is mandatory to reflect students' varied needs and wants as a better program in the future.