This research focuses on the efficiency of the flipped classroom method and its effects on students’ achievement and cognitive load levels. The flipped classroom method is compared to traditional techniques in this study through quasi-experimental research. Participants included 116 prospective teachers assigned to experimental and control groups. The study was conducted over 10 weeks during the 2013–2014 spring semester. Results showed that students taught with the flipped classroom model reported higher learning achievements and lower cognitive loads than those taught with the traditional model. The instructional efficiency scores of the students in the experimental group were also higher than those of the students in the control group. Hence, when designed effectively, the flipped classroom method can be considered a useful approach in higher education settings.