One hundred six Japanese and 169 Egyptian cases of urinary bladder carcinoma treated by total cystectomy were analyzed histopathologically. Urinary bladder carcinomas in Egypt were encountered at an earlier age than those in Japan. The proportion of carcinomas in Egyptian males was higher than in Japanese males. Squamous cell carcinomas (SCCs) predominated in Egyptian cases whereas transitional cell carcinomas predominated in Japanese cases. The pathological stage of Egyptian cancers was more advanced than in Japanese cases; even grade 1 SCCs showed invasion into the muscular layer. Most carcinomas in Egypt were associated with Schistosoma haematobium infections. Acta Pathol. Jpn. 32: 176∼179, 1989.