Recent years have seen the increasing demand of employees' English proficiency from business sectors. As a tool to evaluate English proficiency, TOEIC tests are widely administered throughout the world. Many universities in Taiwan have incorporated business English and test taking skills into their general English curricula in order to improve students' TOEIC scores. This study aims to investigate the effects of a summer intensive English program on participants' TOEIC scores. Students with different majors from various universities of technology were recruited to participate in this MOE sponsored program. The four-week intensive program required participants to stay in the dormitory and attend morning and evening study times besides the daily six-hour, five-day a week English instruction on business related topics and TOEIC preparation material. TOEIC pretest and posttests were administered during the first and last week of the program respectively. Results showed that participants' listening and reading scores improved significantly. Implications of intensive English program and suggestions for pedagogical practices are provided.