This paper investigates the joint effects of intrinsic and extrinsic goals on college students' learning in an introductory psychology course, a biology course, and several social science courses. The study questioned whether higher levels of motivation lead to better student performance. College students were surveyed using the Intrinsic Goal Orientation and Extrinsic Goal Orientation scales of the Motivation Strategies for Learning Questions (MSLQ). Results indicate that students with a medium level of extrinsic motivation are more likely to perform well (in terms of their course grades) than students with either lower or higher levels of extrinsic motivation. Students who combined high intrinsic motivation with medium extrinsic motivation achieve particularly well. The paper suggests that teachers need not eliminate all motivation for good grades in order to achieve both cognitive and lifelong learning goals. (Contains 10 references and one table.) (JDM)