Mental imagery plays a prominent role across psychopathology. However, its quality and role in generalized anxiety disorder (GAD) have not been examined as extensively as in other disorders. The goal of the present study was to obtain a better understanding of general imagery processes and individual differences in people with GAD. Adults with GAD (N = 31) were compared to a Healthy Control (HC) group (N = 32) across mental imagery domains as per Pearson, Deeprose, Wallace-Hadrill, Heyes, and Holmes (2013)'s framework: cognitive, general use/experience, and clinical. No differences were found between the GAD and HC groups on cognitive aspects of imagery. Both groups were also similar in their ability to imagine experiences across sensory modalities. No differences were found between groups in their spontaneous use of imagery in everyday situations, or in vividness of sensory-perceptual imagery. For clinical aspects of imagery, between-group differences emerged in the experience of prospective imagery; those with GAD reported greater "pre-experiencing" ("intrusive, prospective, personally-relevant imagery"; Deeprose & Holmes, 2010), rated imagined future negative scenarios as more vivid, more likely, and more personally relevant, and evaluated the experience of these images as more intense than did HCs. Taken together, findings suggest that the presence of intrusive mental imagery distinguishes individuals with GAD from those without psychopathology. Findings could help improve interventions utilizing imagery techniques.