Less than 140 occupational cancers (OC) are compensated every year in France although the incidence is estimated for at least 6,000 new cases, as estimated by the epidemiologists (4% of the mortality by cancers). This situation can be explained by different factors: few compensation claims by the patients or families, frequent lack of interest from medical doctors for relation between cancer and work, occurrence of the OC after retirement, difficulty to distinguish the role of occupational factors from individual comportmental factors in many OC (for ex. a lung cancer hitting a smoker). The consequences of such a situation are multiple: no compensation for more than 95% of patients or relatives, taking for granted that OC is a minor problem, insufficient prevention of the carcinogenic factors on the work place, prevention of cancers restricted to individual comportmental changes. Physicians working in cancerology units have to incite their patients in notifying the OC and help them in compensation claims. They have also to ask for epidemiologic and toxicologic research when clusters of OC are identified in a plant, in order to get better prevention, compensation and regulations.