The testing effect refers to the phenomenon where testing for a target yields better retention than restudying it. The phenomenon can be explained by an episodic context account that emphasizes the reinstatement of the episodic context for the initial test. The purpose of this study is to investigate whether reinstated context influences the testing effect by manipulating the degree of similarity between targets and their distractors within the initial test. After initially studying the targets, the participants either restudied them or they were tested for them with distractors that either shared or did not share letters with the targets. Finally, the participants underwent a final test either immediately or one week later. The results indicated that a testing effect only occurred for targets that were similar to their distractors. Moreover, as an index of the reinstated context, a similarity effect was also observed for distractors that were similar to the targets. These results suggest the reinstatement of the initial study context plays an important role within the testing effect.