The authors describe an approach to the management of household contacts of leprosy patients and the rationale on which it is based. Initially, all household contacts should be interviewed and examined for symptoms and signs consistent with leprosy and appropriate diagnostic measures taken. Contacts of untreated lepromatous and dimorphous (borderline) leprosy patients are at relatively high risk of disease and should be examined annually for at least 5 years. Dapsone prophylaxis has been shown to prevent secondary cases in contacts up to 25 years old and the authors advise this to be used. Insufficient data exist to support a recommendation for the use of BCG at present.