While debate continues as to the efficacy of Native English-speaking teachers (NESTs) and non-native English-speaking teachers (NNESTs), little research has been conducted to analyze how these teachers impact communicative competence in an EFL context. Research on NNESTs' self-perceptions has been done in many different contexts (for examples, America, Europe, East Asia), but rarely in Thailand. This paper reports on a mixed data collection study which examines the self-perceptions of undergraduate TESOL students in a Thai university. Data were collected through an online questionnaire responded to by 39 undergraduate TESOL students studying in a B.Ed. English program. Seven of these students were selected for semi-structured individual interviews. Findings show that the undergraduate TESOL students were aware of differences between NESTs and NNESTs and perceived both NESTs and NNESTs to have unique linguistic, cultural, and teaching strengths and weaknesses. The finding also shows that the undergraduate TESOL students had positive perceptions towards their non-native status and perceived themselves to be qualified and successful English teachers after graduation. This paper has implications for language teaching expertise and suggestions for developing TESOL degree curriculum and teacher preparation.