To assess the burden of underreporting occupational diseases in Greece. Material-Method Data were collected for the period under study (1996-1999) on employment and occupational diseases registered officially in European countries. Under the assumption that health hazards at work are similar, a prediction of the possible size of underreporting was estimated. Results Approximately 2500 jobrelated diseases are potentially not reported in Greece annually compared to 71requests for pensioning (1997) due to occupational illness referred to the Social
Insurance Institution. In agricultural sector more than 200 cases and in construction industry more than 250 are estimated as the potential burden of underreporting. From another point of view, occupational diseases of the skin, of respiratory system and hearing loss may account for 400, 300 and, 350 cases, respectively. The officially recognized cases in period under study were around 30, 25, and 2, respectively. Eonclusions The fact that occupational diseases are not reported means deficiencies on surveillance system rather than low incidence. In Greece many reasons account for this lack of reporting. Increased awareness and political decision making could restrict this underreporting of occupational diseases.