A 9-year-old Japanese girl with generalized pustular psoriasis (GPP) had a linear epidermal nevus (LEN) which exhibited psoriasislike features in a noneruptive phase of GPP. In advance of the exacerbation of the disease, crops of confluent pustules appeared on the linear lesions and afterwards continued during the flare-up. Although several cases of ordinary psoriasis with a LEN presenting inflammatory changes have been reported, it seems that there is only one paper in the literature concerning pustular formation on a LEN in a patient with GPP. This particular phenomenon may be interpreted as a kind of Koebner reaction in a person with active GPP.