Fibronectin is an important component of the extracellular matrix and serves a role in the pathogenesis of multiple malignancies. The expression of fibronectin also affects the outcome for patients with cancer. The objective of the present study was to determine the clinical significance of the serum fibronectin levels in patients with gastric cancer. A total of 63 patients with a pathologically confirmed diagnosis of gastric cancer were enrolled into the present study. Serum fibronectin concentrations were determined by the solid-phase sandwich enzyme-linked immunosorbent assay method. Age and sex matched healthy controls (n=30) were included in the analysis. The median age at diagnosis was 62 years (range 28-82 years). The baseline serum fibronectin levels of the patients with gastric cancer were significantly higher compared with those in the control group (median values, 606, vs. 193 ng/ml; P<0.001). The known clinical variables, including the age of the patient, gender, site of lesion, histology, histological grade, stage of disease and serum tumor markers, including lactate dehydrogenase, carcinoembryonic antigen and cancer antigen 19.9, were not found to be correlated with serum fibronectin concentrations (P>0.05). In addition, no correlation was observed in serum fibronectin level and response to chemotherapy (P=0.12). Serum fibronectin concentration demonstrated no prognostic role on survival (P=0.43). In conclusion, the serum levels of fibronectin may have a good diagnostic marker in patients with gastric cancer. However, its predictive and prognostic values remain to be elucidated.