Participants read lists of words and then made recognition judgments to pairs of words, each of which consisted of a prime word and a test word. At issue was the effect of a semantic relationship between the prime word and the test word on the recognition judgment to the test word. Under standard recognition conditions, semantic priming impeded correct recognition judgments to new test words and had no effect on recognition judgments to old test words. The overall effect was to reduce the level of discrimination for recognition judgments to the test word. Under conditions in which familiarity assessment would be expected to play a greater role in judgments to old test words, semantic priming facilitated those judgments. The results are explained in terms of a dual process account of recognition.