Universities in Indonesia require students who will complete their undergraduate to write an undergraduate thesis as one of the graduation requirements. From experience, the researcher identifies that there are some challenges in an undergraduate thesis defense. This study wanted to see students’ challenges in undergraduate thesis defense. There was a research question of this study “What are students’ challenges in undergraduate thesis defense?”. This study is a qualitative research using phenomenological research design. The study was conducted at one private university in Yogyakarta, with three participants which were from students of English Language Education Department batch 2014. Based on data collection, this study revealed various findings about students’ challenges in undergraduate thesis defense; nervousness, forget the content of the research, cannot maintain eye contact with the audience, difficult to answer the question. In conclusion, every students had different challenges in undergraduate thesis defense and it can be concluded that students are lack of preparation and confidence.