In the French island of Mayotte in the Indian Ocean, the health and food situation remains contrasted. For a very long time dry beriberi women in postpartum had been suspected and treated. But in 2004 the first infantile epidemic of beriberi was scientifically authenticated and a program of thiaminic supplementation for the pregnant women and infants was set up. In this context, we describe an epidemic of 11 cases of shoshin beriberi among adults between January 2008 and Februar 2009. Over 11 cases of shoshin beriberi, 5 cases were confirmed biologically and 6 were probable. The sex ratio M/W was 0.37. The median age was 34 years. The clinic picture was typical: severe acute dyspnea, an agitation/drowsiness, right cardiac failure: polynevritis of the lower limbs was noted in 9 cases over 11. Biologically it was characterized by a lactic acidosis (average pH: 7.08, lactates: 12.08 mmol/l). The evolution was favorable in the 8 cases which could benefit from early thiaminic refill. The outbreak of an epidemic of shoshin beriberi among adults mainly in groups not having benefited from supplementation shows the effectiveness of the program but also its limits. We compare our series with others: the period from April to June when the food is less diversified, is confirmed as a higher risk period. The programs of nutritional education must be increased and a B1 vitamin supplementation for broader people during the rain season might be discussed.