This study assessed the immune status against diphtheria of a sample of refugees (mainly Kosovars and Kurds) in southern Italy (Puglia). The 54.8% of 1128 subjects showed full protection against diphtheria, 30.1% had basic protection and 15.1% resulted seronegative for antitoxin antibody. Only from 45.9 to 73.9% of 0-10 years old refugees were fully protected while from 12.3 to 24.2% were seronegative to diphtheria with the poorest protection rate among Kurdish children from Turkey. Kosovars showed the highest protection rate to diphtheria whereas data suggest a probable endemic level of diphtheria in Iraq. The screening of refugees revealed a low coverage rate for diphtheria, especially in children, probably due to deterioration of the health service infrastructure or intermittent basic health care in the country of provenience. In terms of public health measures, there is the need of administering booster doses to all refugees coming into Italy and into other host countries to increase the coverage rate against diphtheria. The implementation of the immunization programs against diphtheria in the countries of provenience is also strongly recommended.