10 cases of verrucous carcinoma occurring in different sites were studied clinicopathologically. Clinically, the tumor grew slowly and presented as an ulcerous or cauliflower-like mass. The tumor, existing in the skin, had openings like the sinus tracts on the surface from which foul, grey and greasy material oozed out when pressured. There was no exudation if the lesion grew in the mucosa. Histologically, the tumor was composed of mature and well-differentiated squamous cells showing papilloma-like growth upwards, their epidermal rete showing spheroid expansions downwards. Prickle cell masses invaded into the soft tissue in the deeper layer. In view of the tumors having location either in the skin or mucosa with or without effusion, similar histologic features and biologic behavior, we suggest that the verrucous carcinoma and carcinoma cuniculatum be two different variants of the disease. Finally, its diagnosis, differential diagnosis and treatment are discussed with a review of the literature.