Background: A major goal within physical education is to develop a student who will engage in a lifetime of physical activity. A concept deemed critical and strongly associated with engagement in physical activity is motivation. As such, a number of research studies have been focused on elements that facilitate student motivation in physical education. An area of limited inquiry has been focused on those students with extremely low levels of motivation, also termed amotivated. Therefore, the aim of this study was to examine the impact of teacher instruction, based within self-determination theory (SDT), on the motivational responses of amotivated students. Purpose: The purpose of this study was to examine how different forms of teacher instruction, based within SDT, can influence amotivated students' motivational responses within secondary physical education. Participants and settings: Forty-eight (Male ¼ 18; Female ¼ 30) amotivated students engaged in a compulsory Year-9 sport-based physical education class. Participants were randomly assigned to one of two treatment groups (autonomy-supportive or control). Data collection: Participants' motivational responses were collected using a pretest/ posttest design. Teacher data were collected through the observation and coding of specific behaviors. Data analysis: Data were analyzed through a set of (2 × 2) (Group × Time) Repeated Measures analysis of variances (ANOVAs). Significant ANOVA calculations were placed on a chart to illustrate where the significance was located. Results: Analysis of data indicated that amotivated students engaged in the autonomy supportive classes reported significantly higher levels of self-determined motivation and support for relatedness compared with the control group. Conclusions: Findings from this study provide empirical support for the infusion of autonomy-supportive teaching within physical education. Previous SDT-based instructional studies have reported that teachers who are more supportive have students who report positive experiences and are more physically active. This study extends the SDT body of knowledge by demonstrating the positive motivational change for students with extremely low forms of motivation. Specifically, amotivated students engaged in the autonomy-supportive classes reported significantly higher levels of self-determined motivation and support for relatedness.