Five cases of urachal carcinoma experienced in our hospital during the past 20 years are reported. Surgical resection is considered as the first treatment option of this disease, and other therapies to be less beneficial. Complete surgical extirpation and detection of recurrence in the early stage are considered to be important since local recurrence occurs frequently. We enforced the bladder preserving operation for 4 patients with urachal carcinoma except for 1 case with peritonitis carcinomatosa in the initial diagnosis, and multiple surgical treatment was performed again for 2 patients with recurrence. The bladder was preserved with no evidence of malignancy in three patients for 24, 19 and 5 years, respectively. In the initial management of urachal carcinoma, we believe that bladder-preserving surgery should be considered in selected cases though close follow-up is demanded. Herein, we also report the immunohistochemical study of paraffin-embedded specimens using anti-CEA, CA19-9, CA125 and p53 monoclonal antibodies. The positive reaction was observed in 100% (5/5) for CEA, 80% (4/5) for CA19-9, and 20% (1/5) for CA125. These results suggest that CEA may be a useful marker in the diagnosis of this neoplasm and early detection of its recurrence. Nuclear accumulation of p53 was observed in 80% (4/5), but it did not correlate with the disease progression.