A new murine monoclonal IgG3 antibody (Mab 1H10) was developed with specificity for human cervical carcinoma and several other tumor types. Antibody reactivity against a panel of tumor cell lines was examined by indirect immunofluorescence and quantified by flow cytometry. Mab 1H10 reacted with cervical, colorectal and bladder carcinoma cells and to a lesser extent melanoma and hepatocellular carcinoma cells but did not react with human fibroblasts, lymphocytes or RBCs. Mab 1H10, as assessed by immunohistochemical staining, bound 40/97 cervical carcinoma tissue samples, 8/16 colorectal carcinoma samples as well as a population of osteogenic sarcoma and lung, ovarian and bladder carcinoma tissues. Mab 1H10 did not react with any normal tissue or cell samples tested including cervix, ovary, breast, liver, colon, bladder, lung, spleen, cerebrum, lymphocytes or RBCs. Mab 1H10 may be useful for the targeting of drugs, toxins or radioisotopes to cervical carcinoma in humans.