This study aimed to examine the development of pre-service science teachers' views of the targeted nature of science (NOS) aspects, which are considered more difficult to develop than other aspects. This study was grounded by conceptual change and experiential learning theory. A multiple comparative case study approach was used to explore seventeen pre-service science teachers' views of the targeted NOS aspects through explicit/reflective instruction. This study was carried out within the scope of a science method course allocated three hours per week. Data were collected by using an open-ended questionnaire, follow-up interviews, classroom observations, and reflection essays. Analysis shows the pre-service science teachers had generally naïve and transitional views at the beginning of the study. After intensive NOS instruction focusing specifically on tentativeness, theory/law, and socio-cultural embeddedness of scientific knowledge, the students dramatically developed their views and attained informed understandings in all three NOS aspects. They mostly emphasised the importance of the whole six weeks of NOS instruction including contextualised activities, readings, classroom discussions, lesson plan preparing and presenting, and informal school trips.