Rheumatic fever is declining rapidly in importance in the developed countries, but is still a major public health problem in the developing countries. Primary prevention techniques, consisting of the detection and antibiotic treatment of streptococcal infections of the pharynx, are both feasible and effective, but are also costly, as only 10-20% of all pharyngeal infections are due to the beta-hemolytic Streptococcus, and only a small proportion of those actually develop into rheumatic heart disease. A different concerted approach, which is both effective and economically entirely justifiable, is to use antibiotics as a prophylaxis to prevent secondary infection, i.e. relapses of rheumatic fever. A multi-centre study conducted by the WHO has shown that the cost of antibiotics used for secondary prevention was less than the savings resulting from the lower incidence and shorter hospital stays of recurrencies of rheumatic fever. Given economic restrictions, therefore, priority is given to organized and systematic secondary prevention.