The purpose of this qualitative case study is to investigate the beliefs of a team-teaching native English-speaking teacher (NEST) and a non-native English-speaking teacher (non-NEST) and the extent to which their beliefs are manifested in their classroom practice. The participants are a NEST and a non-NEST who have had one year of experience in team-teaching with each other in an elementary school in Hsin Chu City, Taiwan. The data collection instruments include interviews, belief inventories, classroom observations, and document analysis. Through analyzing the teachers' beliefs in the following areas: (1) advantages and disadvantages of being native and non-native English teachers, (2) team-teaching, (3) roles of the English language, (4) language learning and learners, and (5) teaching practices, the study shows that the two teachers shared many common beliefs, but that their beliefs were not necessarily consistent with their performance in the classroom. Pedagogical implications and suggestions are derived mainly for the benefit of policy makers and for maintaining positive collaboration between NESTs and non-NESTs.