Correlation and regression analyses were used to examine variables that explain the academic motivation of students in St. Lucia based on the theories of future-orientation. A new variable representing individuals’ reactions to the academic opportunity structure (RAOS) in St. Lucia was introduced and tested in conjunction with motivation-related variables from the above theoretical perspectives. Participants were 921 students from 33 classes in four secondary schools in St. Lucia. The results showed that the new variable capturing the reactions to the academic opportunity structure in St. Lucia was a significant predictor of achievement in both mathematics and English. Additionally, students’ self-efficacy predicted achievement in mathematics but not in English. Finally, future orientation and attainment/utility valuing were not direct predictors of achievement. Further research is needed to understand more about achievement motivation in the complex St. Lucian context.