This intervention study investigates the effects of teacher autonomy support on basic psychological needs, self-determined motivation for giving physical education classes and satisfaction from engaging in physical activity. The sample consisted of 61 students (32 in the experimental group and 29 in the control group), aged 12 to 14 years. Two physical education teachers were part of the group, one who was trained to give autonomy-support classes and the other used the usual class model. The experimental group teacher gave classes based on the autonomy support style, while his control group counterpart did not follow any model. The students, assessed before and after the 8-month intervention, were measured for perception of interpersonal teaching style, basic psychological needs, self-determined motivation and satisfaction from engaging in physical activity. The results showed that the experimental group exhibited higher indices for autonomy, competence and relatedness, self-determined motivation and satisfaction from engaging in physical activity, when compared to the control group. The study provides evidence of the effectiveness of programs that support autonomy in physical education classes, emphasizing the importance of pedagogical strategies and educational programs that promote the development of basic psychological needs, self-determined motivation and its positive consequences in relation to physical education classes.