The purpose of this case study is to delve into the complexities of how preservice science teachers' science teaching orientations, viewed as an interrelated set of beliefs, interact with the other components of pedagogical content knowledge (PCK). Eight preservice science teachers participated in the study. Qualitative data were collected in the form of content representation, responses to an open-ended instrument, and semi-structured interviews. Preservice teachers' orientation and PCK were analyzed deductively. Constant comparison analysis of how their orientation interacted with other PCK components revealed three major themes: (1) one's purpose for science teaching determines the PCK component(s) with which it interacts, (2) a teacher's beliefs about the nature of science do not directly interact with his/her PCK, unless those beliefs relate directly to the purposes of teaching science, and (3) beliefs about science teaching and learning mostly interact with knowledge of instructional strategies. Implications for science teacher education and research are discussed.