This paper explores Thai students’ competence in English language and technical knowledge in the relevant fields of their study. It examined the university level Thai students who applied for international internship arranged by International Association for the Exchange of Students for Technical Experience (IAESTE). IAESTE is an international organization which has over 65 years of experience in arranging this program for the students from science, technology and arts fields in over 88 countries and Thailand has become a part of this program for last 33 years. There were 282 applicants from 2009 group and 202 from group 2010 were the participants of this study who represented 21 universities in Thailand. This study analyzes the results of applicants’ qualifying test held in year 2009 and 2010 to see the progress trend and students interest toward IAESTE internship exchange program. Further this study has looked into the correlation between applicant students’ Grade Point Average (GPA), and their performance in English language and technical knowledge. The result reveals that IAESTE is getting more popular among Thai students and the students are putting more efforts to experience such paid international internship which is usually from 3 months to 1 year in length. However, the study found weak positive association between GPA and students performance during their qualifying test.