The aims of this study were to appreciate how frequent asthma was named in the legal list of worker's compensation, state hazards and occupations involved and appreciate conditions required for a legal recognition of the disease. The study consisted of a review of the legal list of occupational diseases of all tables where asthma was stated. Medical, technical and administrative criteria allowing compensation were looked for. Asthma was listed in 12 among the 67 tables; causal substances listed were known as sensitizers and included mainly organic and metallic compounds. Numerous occupations were concerned in all primary, secondary and tertiary sectors. Medical conditions refered to "all asthma confirmed by functionally respiratory tests or regenerated by a new exposure". Time length of declaration was seven days. Variety of occupations concerned and numerous substances involved should invite to look for occupations in all patients with asthma. Physicians should be aware of theses legal conditions in order to recognize better occupational asthma and ease it legal compensation.