In this issue of the Journal, Kirchberg et al. (7) report a study that compared the integrity of semantic memory in 25 patients with amnestic mild cognitive impairment, 27 mildly demented patients with Alzheimer’s disease, and 70 healthy comparison subjects. Semantic memory was assessed with a semantic distance task in which participants had to judge which of two entities, presented as images or words, was larger in the real world. Semantic distance was manipulated by adjusting the disparity in real-world size between the two entities that were being compared. Entities similar in real-world size have a small semantic distance (e.g., a key versus an ant), whereas those with a large size disparity have a large semantic distance (e.g., a house versus an ant). Images were presented in two conditions: congruent, in which the image of the larger real-world object was larger than the image of the smaller object (e.g., a house pictured larger than an ant), and incongruent, in which the image of the smaller object was larger than the image of the larger object (e.g., an ant pictured larger than a house). Results revealed that the Alzheimer’s disease and mild cognitive impairment groups were less accurate and slower than the healthy comparison group in making semantic decisions for word stimuli, and this deficit worsened as the sizes of the compared objects became more similar. The same result was found for images when collapsed across congruent and incongruent conditions, but only for accuracy. The image effect was largely driven by the incongruent condition in which patients with mild cognitive impairment performed similarly to healthy subjects in tasks with large semantic distances and similarly to Alzheimer’s disease patients in tasks with the more semantically demanding small distances. The semantic memory deficit demonstrated by this study adds confidence to the growing perception that subtle decline in this cognitive domain occurs in patients with amnestic mild cognitive impairment. Because the task places minimal demands on the effortful retrieval process, overt word retrieval, or language production, it also suggests that this deficit reflects an early and gradual loss of integrity of semantic knowledge.