Helicobacter pylori infection (HPI) is known as a risk factor for gastric cancer. Nitric oxide is produced during non specific defensive events of immune system. In carcinogenesis theories, although the association is known, the role of Helicobacter pylori (HP) in etiology of gastric cancer remains unclear. In this study we examined the serum nitrite contents of female patients (n=46) who were diagnosed to have gastritis endoscopically and the control group of healthy females (n=10). Nitrite levels were significantly higher in HP IgA-IgG positive group, and in conclusion, if women are known to be under significant risk of gastric cancer, periodically monitoring the serum nitrite levels (or nitric oxide synthase activity) of every female patients with HPI during the treatment period may be a valuable marker for a possible gastric cancer risk despite of the possible eradication of the bacteria.