This thesis aims to investigate teachers' strategies and challenges in integrating 21st century skills through traditional seating arrangements. The participants were two teachers at SMAN 03 Semarang. This research is descriptive-qualitative research where the main data is obtained from observation and interview. Data analysis in this study includes the stages of data reduction, data display, and conclusion drawing. This study concluded that the teacher's strategy in integrating 21st century skills through traditional seating arrangement is more directed to how the teacher makes students active in learning with the prepared learning methods. Then, for the seating arrangement, only one pattern is applied, namely the traditional seating pattern. And this is a challenge for teachers in integrating 21st century skills because it only applies one seating pattern. Where other seating patterns can be more effective or support the integration of students' 21st century skills. And it is hoped that teachers can apply other seating arrangements to support the integration of students' 21st century skills and reduce teacher challenges in integrating them.