The interest for the problematics linked to the stress in work environments has been till now limited to the consideration of its effects on health, even if the D.Lgs 626/94 obliges the employer to evaluate also the psyco-social risk, as has confirmed a sentence of the European Court of Justice. The present survey, lacking valid instruments to be found in literature, aims to experiment and evaluate a principle for the identification of causes, thus creating a model for the evaluation of risk also according to the indications published in the Document for the Consent of SIMLII in 2005, which can be used by Prevention and Protection Services and by Competent Medical Doctors. In the area of risks evaluation and of the attainment deriving from them. The model of evaluation of the risk deriving from work organization (stress), object of the present survey, has been sperimented in a sample composed of 268 employees in 13 municipal administration belonging to biographically known categories for stress risk afferent to 23 homogenuous organizational structures (traffic officers and nursery school teachers). The valued risk has been introduced in the VDR document and the indications for the sanitary surveillance have been formulated.