This study examined how frequently psychology professors at liberal arts colleges assign primary source readings. Professors provided information on 576 courses. Frequent use of primary sources suggests that professors view such readings as a valuable component of the psychology curriculum. Professors assigned primary source material in 70.8% of the courses. Professors assigned articles from scholarly journals more often in higher level courses and courses with lower enrollments. Professors reported more satisfaction with the classroom discussion of primary sources in smaller, more advanced courses. This study also provides a list of readings identified most frequently by participants as being effective.