Pemphigus vulgaris rarely occurs in children. We present the youngest reported case. All six cases of childhood pemphigus vulgaris proven by biopsy began with lesions confined to the oral mucosa. In each case diagnosis was delayed until the more typical cutaneous lesions began to appear. Either mucosal or cutaneous biopsy specimens are diagnostic, and early biopsy of erosive mucosal lesions is indicated. Vigorous therapy with systemic steroids is important in the prevention of fatality.