We previously established (K. Sonoda et al., Int. J. Oncol., 6: 1099-1104, 1995) a novel monoclonal antibody, 22-1-1, generated from adenocarcinoma of the uterine cervix, and 22-1-1 antigen (Ag) was expressed in cancer cells derived mainly from the uterus and ovary. In this report, a relationship between 22-1-1 Ag expression and clinicopathological variables and the prognostic significance of 22-1-1 Ag were immunohistochemically investigated in adenocarcinoma of the cervix. Of 56 cases, the 22-1-1 Ag was negative in 7, 1+ in 14, 2+ in 26 and 3+ in 9 instances. The 22-1-1 Ag existed both in the cytoplasm and on the membrane of cancer cells. There was no correlation between 22-1-1 Ag expression and age, stage, grade, myometrial invasion, lymph-vascular space invasion, lymph node metastasis, and parametrial invasion. The estimated 5-year overall survival (OS) of patients with low 22-1-1 Ag expression (-/+) and high 22-1-1 Ag expression (++/ ) were 90.5 and 71.4%, respectively. Patients with high 22-1-1 Ag expression had significantly worse OS than those with low 22-1-1 Ag expression (log-rank test, P = 0.0193). In addition, lymph-node metastasis, age, and clinical stage were significantly related to OS in univariate analysis. Multivariate analysis for OS revealed a prognostic significance in 22-1-1 Ag expression, stage, age, and grade. These data suggest that 22-1-1 Ag expression may be related to prognosis in adenocarcinoma of the cervix.