In a number of studies, interteaching has produced better student-learning outcomes than traditional teaching methods. Little research, however, has examined ways to make interteaching more effective. Research on the testing effect suggests that frequent testing may improve performance. Thus, including postdiscussion quizzes as a part of interteaching might enhance its efficacy. In this study, college students completed an interteaching session in a simulated classroom setting. Some students completed a postdiscussion quiz, whereas others completed anagrams. All students returned 1 week later to take another quiz over the material they had discussed the previous week. Students who completed postdiscussion quizzes had significantly lower quiz scores than students who completed anagrams. Thus, postdiscussion quizzes may not enhance the efficacy of interteaching.