In March 2011, a 40 year-old French man was diagnosed with diphtheria caused by toxigenic Corynebacterium diphtheriae. Fifty-three close contacts were identified from whom throat samples were analysed. C. diphtheriae was found only in the asymptomatic partner of the index case. The two cases had travelled in Spain during the incubation period of the index case. Investigation around the second case identified 13 new close contacts.None of them was found to be infected.