Research shows that Remember and Know judgments are effective measures of recollective experience. This article shows that Know responses can be selectively affected by fluency of processing that is created using a conceptual manipulation. In a recognition test, studied and nonstudied words were preceded by semantically related or unrelated primes. Participants gave significantly more Know judgments to items with related primes than unrelated primes but Remember responses were unaffected. Know responses are discussed in terms of familiarity assumed to arise from fluency of processing which, in turn, may be created through various sources including conceptual processes.