The importance of teachers' technological, pedagogical, and content knowledge (TPACK) in conducting effective technology-enhanced instruction has been recognized; however, the understanding of teachers' TPACK when teaching English as a Foreign Language (EFL), as well as the need for their further TPACK development, has not been properly addressed. To fill the gap in TPACK research in the EFL domain, this study aims to explore the TPACK among 22 in-service EFL teachers at elementary schools in Taiwan. Also, the possible needs of these EFL teachers for their future professional development were investigated. In order to better portray the TPACK of the EFL teachers, both their synthesized TPACK and performance on the seven TPACK construct components were evaluated in this study. A quantitative questionnaire was used to assess the EFL teachers' performance on the seven TPACK construct components. Their synthesized TPACK was revealed by means of interviews and classroom observations. The Revised Bloom's Taxonomy and the pedagogic framework for computer-assisted language learning were used to analyze the qualitative data collected from the interviews and class observations. The results indicated that the EFL teachers needed more technology knowledge to further develop their TPACK, and that the EFL teachers' TPACK focused much on motivating students, rather than on using technology for creating opportunities for students to use English language meaningfully and authentically.