The question of whether hypochondriasis (HYP) should be considered a somatoform disorder (SFD) or classified as an anxiety disorder (ANX) has recently been raised. To empirically provide information on this issue, we compared patients with HYP (n = 65) with those with other SFDs (n = 94) and those with ANX (n = 224) regarding sociodemographic and biographical variables, general psychopathology, and naturalistic cognitive-behavioral therapy treatment effects. Compared with SFD, patients with HYP were younger and had fewer comorbid affective disorders and less impaired life domains, suggesting a closer connection between HYP and ANX. Regarding cognitive-behavioral therapy treatment effects, all diagnostic groups showed comparable significant improvement (d = 0.44-0.64). According to level of anxiety, the SFD sample had significantly lower pretreatment scores than did the ANX and the HYP samples. The results suggest that patients with HYP have an interim position between SFD and ANX, with slightly closer connections to ANX.