A Questionnaire on sleep and vigilance disorders has been developed by the Italian Association of Sleep Medicine to help the occupational health physicians in screening for sleep disorders. Aim of this study was to compare the Questionnaire with standardized questionnaires for sleepiness and sleep apnea and with a polysomnographic evaluation. Four hundred sixty-three (463#) commercial bus drivers (454M, 9F; mean age +/- S.D. 41.6 +/- 8.1 yrs; mean body mass index 26.2 +/- 3.6 kg/m2) underwent clinical evaluation that included the Italian Association of Sleep Medicine Questionnaire on sleep and vigilance disorders and two standardized questionnaires (Berlin Questionnaire and Epworth Sleepiness Scale). According to the Italian Association of Sleep Medicine Questionnaire on sleep and vigilance disorders 40 subjects presented an high risk for sleep disturbance and in 28 subject the questionnaires were concordant. Preliminary results (16 patients) showed an high rate of concordance between questionnaire and PSG. These data strongly suggest that sleep disorders and symptoms, that are frequent in a population of professional bus drivers, should be better evaluated during occupational health visit.