We investigated Tanzanian primary school students' action-control beliefs about school performance using the revised Control, Agency, and Means-Ends Interview (CAMI) and school experiences controlling for the effects of parental educational level, gender, and age. Five hundred forty-five students (254 boys and 291 girls) in grades 3 through 7 from both urban and rural schools responded to the CAMI questionnaire in Swahili. A structural equation model validated the dimensions of action-control beliefs, thereby supporting the idea that these constructs are basic education-related aspects of human belief systems across cultures. The Tanzanian educational system and teaching format were reflected in low performance-belief relationships. Higher achievers were more prone to develop an adaptive belief profile (internal causes: effort, ability) and more positive perception of their teachers, whereas low achievers were more prone to develop a maladaptive belief profile (external causes: luck, teachers, and unknown), and more social anxiety.