The effects of graduate students' peer orientation on achievement and motivation to learn with cooperative learning strategies while enrolled in a 1-semester educational research methods course were investigated. During 15 weekly lessons (2 hr and 50 min each), students with high and low peer orientation were exposed to cooperative-learning instruction that involved face-to-face promotive interaction, positive interdependence, individual accountability enforced by group members, collaborative skills, and group processing. At the end of the course, the students' achievement and motivation levels were assessed. Differences in the achievement of students with high and low peer orientation were not statistically significant. However, students with high peer orientation were significantly more motivated to learn than were students with low peer orientation. Potential causes and ramifications of the findings are discussed.Key words: cooperative learning, motivation and achievement, peer orientation