The purpose of this study was to examine the interactions between in-service chemistry teachers' science teaching orientations and other components of their pedagogical content knowledge (PCK). Two experienced chemistry teachers participated in this study. Data were collected through interviews, classroom observations, and field notes as the participants taught the mixtures unit. The results indicated that the participants held solid foundation purposes, in which students use science to be successful in their exams or next classes, along with everyday coping and correct explanations purposes. When participants' correct explanations and solid foundation purposes interacted together with the same PCK component, solid foundation appeared to be the reason for their correct explanations purpose. The teaching strategies that teachers preferred to use interacted with their solid foundation and correct explanations purposes, and the participants altered curricula only if they believed it would lead students to achieve better scores on examinations. Participants' beliefs about science teaching and learning indicated aspects of teacher-focused beliefs that prevent teachers from focusing on students' prerequisite knowledge, learning difficulties, and misconceptions. These beliefs interacted with all the sub-components of knowledge of instructional strategies. In addition, there was an interaction between knowledge of curricula and beliefs about science teaching and learning for participants that were more knowledgeable about the curriculum. Moreover, what the teachers assessed was related to their correct explanations and everyday coping beliefs, while the way they assessed was related to their solid foundation beliefs. Last, none of the participants emphasised the aspects of the nature of science during their instruction.