Health preoccupations are present in both generalized anxiety disorder (GAD) and hypochondriasis. Contrary to GAD, in which excessive anxiety and worry encompass a number of events or activities, health is the central theme of worry in hypochondriasis. A recent study demonstrated that two processes involved in GAD are also involved in health anxiety. In light of these findings, adapting the treatment for GAD to hypochondriasis was warranted. In the present study, 6 hypochondriacal patients participated in a multiple baseline single-case design. Patients were assessed by means of a structured interview before and after treatment. Treatment targeted the following components: (a) awareness of worry, (b) intolerance of uncertainty toward health, (c) faulty beliefs regarding worry and anxiety, (d) cognitive avoidance and relapse prevention of reassurance or avoidance behaviors, (e) poor orientation to physical symptoms and problems, and (f) relapse prevention. Following treatment, none of the 6 patients met criteria for hypochondriasis. Results confirmed that a treatment targeting excessive worry is effective for hypochondriasis. All participants reached a high end-state functioning at the 1-year follow-up. The clinical implications of these results are discussed.