The testing effect occurs when a person's memory performance is enhanced by previous tests. The current studies examined the performance effects of a classroom testing procedure on high and low performing students and their transfer of learning. Hypotheses: We predicted testing in the classroom would lead to a testing effect and transfer of learning but did not make specific predictions about the effect of student aptitude due to previously mixed findings. Study Design: Students in a psychology course completed unit exams and a final cumulative exam. Students could re-answer questions that were the most frequent incorrectly answered on the exam (Frequent Incorrectly answered Questions, FIQ) from each unit exam during an in-class testing activity following that exam. On the final cumulative exam, students answered the FIQs and non-FIQs (Study 1) or FIQs in multiple transfer conditions (Study 2). Proportional performance change on each question type was the dependent variable. Major Conclusions: Both high and low performing students' performance on FIQs increased compared to non-FIQs (Study 1). Performance in the Near Transfer condition was significantly greater than the Same Questions and the Far Transfer condition (Study 2). The findings presented here add to the evidence that supports testing in the classroom because it both facilitates longer term retention of the learned material and transfer of learning.