OBJECTIVE Fibronectin (FBN) is involved in the motility and migration of malignant cells. The purpose of this study was to investigate FBN plasma levels in gynecological cancers patients and in healthy women. METHODS The study took place between 1998 and 2003. One hundred women with histologically diagnosed cancer of gynecological organs (cervix, ovary, endometrium, breast) formed the study group (group A), whereas the control group (group B) consisted of 100 healthy women. FBN plasma levels were measured with the radial immunodiffusion method. RESULTS The average age of group A patients was 42.08 years (range 33-77), and of group B it was 41.1 years (range 32-65). Both groups were compared with the Student's-t test. The median plasma value of FBN in all gynecological malignancies was 258.4 mg/l (standard deviation/SD 163.9, p=0.0066, t-statistics: 2.768, (t95): 1.984, 95% CI: 225.4-290.9). The plasma levels were significantly elevated when compared to the control group (median=213 mg/l). The distribution of values showed a statistically important "tail" in high plasma levels (FBN >400 mg/l). Plasma levels of FBN were more increased in breast and cervical malignancies when compared to ovarian and endometrial cancers. CONCLUSIONS FBN plasma levels were significantly increased in the total of group A patients, but not significantly increased in the endometrial and ovarian subgroup. Whether or not FBN could reliably be a marker for gynecological cancers should be confirmed in studies with larger number of patients.