Psychologists consider student engagement as a primary pathway by which motivational processes contribute to students' learning and development (Connell & Wellborn, 1991). Academically engaged students self-regulate their learning, make plans for upcoming tasks, and persist when encountering obstacles and challenges. The present study intends to analyses the relationship between students' motivation and engagement and their academic satisfaction and test the effect of some variables (gender, class) on that relation. To accomplish these purposes, this study intends to investigate Malaysian primary school students' motivation, engagement and achievement satisfaction as predictors of achievement satisfaction in science and test the effect of some variables (gender, grade) on that relation. The students - 460 students (43% male, 57% female) of secondary school-responded to the Self-Developed Academic Satisfaction Questionnaire, Students' Engagement Questionnaire and Science Motivation Questionnaire. All the questionnaires are valid and reliable according to the Cronbach's Alpha value. A Multiple linear regression analysis has been used to predict the achievement satisfaction of Science based on the level of students' motivation and level of engagement in Science classroom. The findings showed that students have a good level of motivation, engagement and achievement satisfaction. Even though students' motivation is significantly predicted students' achievement, but neither students' engagement nor achievement satisfaction are a significant predictor of students' achievement.