Immunosuppression and transplantation have been reported to induce porokeratosis (PK), especially its variant, disseminated superficial PK (DSP). On the other hand, there is ample evidence of a relationship between hepatitis C virus (HCV) infection, liver cirrhosis (LC), and hepatocellular carcinoma (HCC). We report 3 cases of DSP in which the outbreak of DSP was suspected to have occurred during the development of HCC in patients with HCV-positive LC. The patients had undergone ultrasonographic study regularly, and no signs of malignancy had been found before the development of DSP. Their outbreaks of DSP were very acute, and the period between the development of DSP and diagnosis of HCC ranged from 2 to 6 months. The association of HCV-related HCC and DSP has never been previously reported. HCV-induced immunomodulation or its effect on the p53 system may be the basis for this type of association. It is necessary to consider development of HCC whenever DSP is found in HCV-positive patients. DSP may be a new paraneoplastic dermadrome. (J Am Acad Dermatol 2000;43:966-8.)