Indirect evidence suggests that worry primarily involves thought, rather than imaginal, activity, a distinction within cognitive process that is potentially crucial to some theories of anxiety maintenance and modification. The present study contrasted the frequencies of reporting the presence of thoughts and images among generalized anxiety disorder clients and matched, nonanxious control subjects during a self-relaxation period and a worry period. Repetition of the assessment was conducted with clients after they completed 12 sessions of therapy. Sampling of mentation during these periods revealed that (a) during relaxation, nonanxious subjects reported a predominance of imagery whereas clients show equal amounts of thought and imagery, (b) nonanxious subjects shifted to a predominance of thought during worry, and (c) clients showed a normalization of thought and image frequencies after successful therapy. This combination of results suggests that worry is principally thought-like in content. The speculation is offered that worry may function as motivated avoidance of emotional imagery and its attendant somatic sensations.