Chemistry-related courses cover a wide range of disciplines focusing on the application of Chemistry. The purpose of this study was to determine factors affecting student's future intention to enroll in chemistry-related courses in the Philippines. A total of 953 senior high school students from the Philippines answered an online questionnaire consisting of 42 questions. Several factors, such as attitude towards laboratory, attitude towards chemistry, affective, autonomy, relatedness, competency, perceived behavioral control, and future intentions, were analyzed simultaneously utilizing Structural Equation Modeling (SEM). SEM indicated that affective behavior affected by attitude towards chemistry was found to be the most significant factor on student's future intention to enroll in chemistry-related courses, followed by autonomy, and competence to perceived behavioral control. Interestingly, attitude towards laboratory and relatedness were found not to have significant effects on student's future intention. This study integrated the self-determination theory and theory of planned behavior among senior high school students to determine factors influencing students to enroll in chemistry-related courses in the Philippines. The findings can be utilized as a theoretical foundation particularly for enhancing the enrollees of chemistry-related courses. In addition, the approach can also be utilized to evaluate other courses for future intentions to enroll.