Two outbreaks of trichinosis occurred in France in 1985 and 1,073 cases were identified. These outbreaks were related to the consumption of parasitized horse meat. The medical and social cost of these outbreaks have been estimated with a sample of 92 patients. The average medical cost was 1,200 FF by outpatient and 17,300 FF by hospitalized patient. For the 1,073 cases, the total cost of these 2 outbreaks is estimated to have been between 7 and 11 millions FF. Of this sum, the hospitalization fees exceeded 51% and the social cost was 36% (loss of productivity). Since October 1985, a decree of the French Ministry of Agriculture has imposed a parasitologic test on all horse carcasses slaughtered in France or imported. This examination costs under 5 FF (under $1) per carcass. This study shows that the systematic examination for trichinosis of horse meat carcasses should be continued and that more sensitive screening methods should be developed.