This paper presents the results of a study of the relationships between the personality types of a group of English as a foreign language (EFL) students in Indonesia and various measures of their academic performance in a semester‐long course including a series of EFL language measures.Students were the entering class of English majors (N=76) at a university in Indonesia in the fall of 1991. We tracked them through their performance in an Integrated Course, a 9‐hour‐per‐week intensive basic course they needed to pass in order to move on to any second semester or higher course. The course is team‐taught in 3 sections of students, with 3 teachers teaching each section.We gave the students the Myers‐Briggs Type Indicator (MBTI), which had been translated into Indonesian. We report and discuss the validity and reliability of using this as a measure of students’ personality types. In addition, we tested the students monthly on reading comprehension, vocabulary, grammar, and writing.Results show that these EFL students are almost evenly divided between Extraverts and Introverts, with over 50% of the students being 1 of 2 (out of 16 possible) types: ESTJ (37%), ISTJ (21%). The distribution of types for these EFL students is similar to those of ESL students in similar studies. Although extraversion and introversion are related to vocabulary and composite course scores, there are few other direct relationships between learners’ personality types and their language performance. We discuss implications for further research, as well as for EFL