The purpose of the study was to test the effect of reading literacy questioning training on Turkish language teacher candidates' PISA-style question preparation. The training was carried out with 55 volunteer Turkish teacher candidates studying at the Turkish Language Teaching undergraduate program of Bursa Uludag University. The training sessions with participants within the framework of the study lasted for 7 weeks in the fall semester of the 2019-2020 academic year. The study was conducted with a nested experimental design, which is one of the mixed methods. As a data collection tool, a test with 6 texts for the participants to ask questions and classify them was used. Furthermore, a semi-structured interview form was used to specify the development of the participants in the training process. The data related to the test were analyzed using descriptive statistics, t-test, Wilcoxon signed-rank test and Cohen's d formula, and the interview data were analyzed by the descriptive analysis method. Based on the analysis, the training had a significant effect on the participants' preparation of PISA-style questions and in increasing the success of classifying PISA-style questions according to the PISA framework. It was found that there was a significant increase in the number of questions asked by the participants after the training and in the number of questions for high-level competencies. After the training, the participants stated that they considered themselves competent in classifying questions rather than preparing PISA-style questions. However, they also stated that the training period was insufficient. The research findings revealed that teacher candidates needed pre-service questioning training and this need should be met. It is recommended that longer period of time be devoted to training for future studies.