It has been well established for several decades that semantic organization of study materials greatly enhances recall by facilitating access to information during retrieval. However, the effect of organization on recognition, and its relationship to the effect on recall, is in doubt. We report the first direct comparison of the effects of categorically organizing study lists on recognition, cued recall, and free recall. We found that whereas organization improved recall, it impaired recognition. Organization had a larger effect on free recall than on cued recall. Within the categorized lists, recall was superior for items highly associated with the category; the opposite was true of recognition. In recall, organization improved the proportion of categories recalled, but it lowered the proportion of items per category recalled. A simple framework for interpreting the dissociation is offered. Possible mechanisms underlying the detrimental effect of organization on memory and prospects for future research are briefly discussed.