The aim of this study is to determine the effect of a textbook preparation process supported by instructional technology tools on the TPACK (Technological Pedagogical Content Knowledge) self-confidence level of prospective Social Studies teachers. The research was carried out using a sequential descriptive design with a mixed method design. Quantitative data were collected before and after the implementation process and the qualitative data were collected after the implementation process. Quantitative data were collected by the Technological Pedagogical Content Knowledge (TPACK) Self-Confidence Scale; and qualitative data were collected by a metaphor form and a BLOB tree self-assessment form. Quantitative data were analyzed by a Paired Samples t-test and qualitative data were analyzed by content analysis. A total of 53 prospective Social Studies teachers, from a public university in Turkey, participated in the research. The results of the analyses showed there were statistically significant differences between pre-test and post-test scores in the levels of TPACK self confidence amongst prospective Social Studies teachers. The self-confidence scores were in favor of the post-test. Furthermore, while prospective teachers have created negative metaphors about their TPACK self-confidence before the implementation process, they created more positive metaphors after the implementation process. According to the results of the BLOB tree self-assessment, it was revealed that the TPACK self-confidence levels increased amongst the prospective Social Studies teacher participant group.