This research was aimed at investigating the types of warming up activities and the most dominant warming up activity used by EFL teachers. This is a case study with 3 English teachers of a private school in district Banyumas participated. Both observation and interview were used as the instruments of the research. The data collected were processed and analyzed by using descriptive method. Through 7 times observation in 7 EFL classes and 3 times interview with 3 English teachers, it is found that there were 5 warming up activities implemented: Question-Answer, Show a Picture, Tell a Story, Spin a Marker and Show a Video. Moreover, the most dominant activity that is used by the teachers is Question-Answer.