The purpose of this paper is to investigate the effectiveness of pedagogical content knowledge (PCK)-based nature of science (NOS) teaching on pre-service science teachers' (PSTs) NOS views. The study is grounded by conceptual change and experiential learning theory. It is also framed by the teacher professional knowledge and skill (TPK&S) PCK model. This is an exploratory case study of PSTs' developments during a 14-week course to teach about NOS. Each participant's views of NOS and changes on these views were investigated as a multiple comparative case study. Thirty-nine PSTs participated. Multiple data collection includes open-ended questionnaires, interviews, classroom observations, lesson plans, and reflective essays. Questionnaire responses and interview transcriptions were analyzed using the NOS views continuum scale. The remaining data including lesson plans and reflective essays were analyzed using content analysis. According to the analyses, most of the PSTs started the course with naive views about the NOS aspects at the beginning of the study. After attending the PCK-based NOS instruction, almost all of the PSTs dramatically developed their understandings of NOS, and they maintained their informed views a year later. The results of show that PCK-based NOS teaching was very effective and successful for improving PSTs' NOS understandings and maintaining these views in the long term. The findings have the potential to translate as practical advice for teachers, science educators, and future researchers.