Objective. Occupational/mental stressors, which may be evaluated with measurements of salivary cortisol concentrations, affect the endothelial function and has implications on cardiovascular health. Nitric oxide (NO) is known to have an important role in cardiac function and may also be assessed in the saliva, but its participation in physiological responses to hypothalamic-pituitary-adrenal (HPA) axis stimulation is still not completely understood. The aim of the present study was to test the hypothesis that salivary NO (as nitrite) and cortisol concentrations in school teachers vary throughout the academic year.