To motivate students, intrinsic interest is generally preferred over the instrumental values (useful for future study/work) of the tasks. Such general principles could be complicated by the differential work-related values and attitudes across cultures. Understanding and applying the appropriate motivational systems in congruence with students' cultural beliefs is important. Using self-determination theory, we examined the possible differential importance (and other complicated interactions) of motivational factors in representative student samples from 19 countries and economies in two cohorts of large-scale international surveys (in total 188,481 students in the Trends in International Mathematics and Science Study [TIMSS], 2015 and 2019). Results showed that emphasizing task instrumental values helped academic performance for students with a low intrinsic interest in collectivistic cultures. In contrast, stressing instrumental values did not help low-interest students in individualistic cultures. Notably, intrinsic motivation facilitates academic performance universally in all cultures.