The purpose of this study was to examine the effects of a blended teaching-learning approach on academic achievement and twenty-first century skills of preservice teachers who took the teaching principles and methods course. The implementation was carried out over a period of ten weeks with preservice teachers who were enrolled in pedagogical training at the Faculty of Education at Karamanoglu Mehmetbey University in the 2019-2020 academic year. In the study, a semi-experimental research design with experimental and control groups was employed. Data collection tools were an academic achievement test and "multidimensional twenty-first century skills scale". Analysis revealed that there was a significant difference across the two groups' academic achievement and twenty-first century skills in favor of the experimental group. In addition, analysis of the retention test administered four weeks later showed a significant difference in favor of the experimental group. In the light of the results, the implications and future directions were discussed.