A flipped classroom, as one of the participatory learning techniques, is based on group dynamics and social interactions. The present study aimed to investigate the effectiveness of the flipped classroom technique in promoting academic motivation and self-efficacy among high school students. The research method was quasi-experimental with a pre-test and post-test design and a control group. The statistical population included all female high school students in Ahvaz city in the academic year 2019-2020. Using the purposive sampling method, 30 ones were selected and divided into experimental and control groups (n=15 per group). The research instrument included the Academic Motivation Questionnaire and Student Self-Efficacy Scale. The experimental group received the flipped teaching program during eight 90-minute sessions; however, the control group received the traditional teaching method. Analysis of covariance (ANCOVA) was used to analyze the data. The results indicated that there was a significant difference between the flipped and traditional teaching methods in experimental and control groups (p<0.0001). The flipped classroom technique was effective in increasing academic motivation and self-efficacy among students. The study findings indicate that the flipped classroom method can be used to promote academic motivation and self-efficacy and decrease academic failure among students.