Bowen's disease has been viewed as a skin marker for internal malignancy by dermatologists for decades. If substantiated, it certainly would help in early detection of an occult malignancy. We conducted a matched case-control study to evaluate the significance of this link. Ninety patients with Bowen's disease diagnosed between 1972 and 1986 were selected for study. These patients were matched by age, sex, race, and date of biopsy for diagnosis (or treatment) to 90 other patients chosen as controls. Six patients in the Bowen's disease group and three patients in the control group had internal malignancy during the period after the date of biopsy or treatment (P > 0.4). The present study cannot substantiate the claim that Bowen's disease is a skin marker for internal malignancy.