Two studies investigated the relationship between parental support, students' motivational orientations, and students' emotions during homework. It was assumed that intrinsically motivated students would feel better when parents provided much learning autonomy, while extrinsically motivated students would experience more positive affect when directive parental support was given. In study I, students (N=181) reported their emotions after having read two vignettes (autonomy-supportive vs. directive parental support). In study II, 38 students reported their motivation, the perceived quality of parental support, and their emotions after each of 21 homework sessions. Results of extreme group comparisons (intrinsic vs. extrinsic motivation) partly supported the assumed Aptitude-Treatment-Interaction: Even when students' academic self-concept was controlled, extrinsically motivated students tended to report more negative affect than intrinsically motivated students under autonomy-supportive conditions; for directive parental support, the reverse trend was discovered. Consequences for homework interventions are discussed. (Contains 6 tables.)