We performed a serologic analysis for anti-murine double minute-2 (anti-mdm2) antibodies in sera of patients with different gynaecological diseases using immunoblotting technique with recombinant mdm2 as antigen. In addition, for large scale screening we established an anti-mdm2 enzyme-linked immunosorbent assay (ELISA). Serum samples from patients with breast cancer, ovarian carcinoma, cervix carcinoma and benign gynaecological tissue alterations were tested. We detected antibodies specific for mdm2 in sera derived from cancer patients, as well as from patients with non-malignant diseases. Some of the sera with antibodies against mdm2 also contained antibodies against the growth suppressor gene product p53.