The purpose of the study is to investigate how pre-service elementary teachers' orientation about science inquiry impacts their implementation of inquiry-based instruction. Teaching orientation is one of the levels of pedagogical content knowledge (PCK) which impacts on teachers' instructional practice. With thirty-one pre-service teachers, data are collected using a survey and three vignettes and are analyzed using a correlational coefficient. The results show that: (1) there is a moderate relationship between pre-service teachers' view of inquiry-based instruction and their willingness to implement it; (2) pre-service teachers' confidence in implementing inquiry-based instruction increases as they gain experience with inquiry-based methods through coursework; and (3) the participants favor using inquiry methods, but they feel more comfortable with a more teacher-centered approach. It implies that one science method course may not suffice to produce teachers who are self-efficacious about teaching inquiry-based science. Thus, they need additional instruction to implement a more student-centered inquiry approach.