Science process skills (SPSs) are one of the most important skills possessed by students in conducting scientific activities. Therefore, it is crucial for science teachers to understand and practice these skills. Considering the role of teachers in developing students' SPSs, the focus of this study is on developing pre-service science teachers' SPSs. This study aims at determining the effects of explicit teaching of SPSs upon pre-service teachers' SPSs. To accomplish this, action research was employed. The study involved 10 pre-service science teachers who voluntarily participated in the study and were from Science Education Departments at a state university in Türkiye. Data were collected by using two methods: quantitative and qualitative. The quantitative data were obtained by using the Science Process Skills Scale. Meanwhile, the qualitative data were obtained from semi-structured interviews and diaries. The Wilcoxon Signed Rank Test was utilized in the quantitative data, and a content analysis technique was used in the analysis of the qualitative data. The results of the study indicated that explicit teaching of SPSs contributes to the development of pre-service teachers' SPSs, and that all preservice teachers prefer explicit teaching in the teaching or development of SPSs.