With introduction of penicillin and improvement of socioeconomic status, severe group A streptococcal (GAS) infections and their sequelae declined dramatically since 1970s. However, there have been worldwide reports on the increase in invasive GAS infections and the resurgence of rheumatic fever since mid-1980s. Necrotizing fasciitis and streptococcal toxic shock syndrome produce marked hypotension and fatal outcome with multiorgan failure. Mortality rate is over 30% in spite of intensive antibiotic treatment and surgical debridement of necrotic tissue. Scarlet fever is not uncommon, but toxic or septic scarlet fever is rare. In Korea poststreptococcal glomerulonephritis (PSGN) is increasing in Chinju city since 1994, while M12, a nephritogenic strain, was more common in Chinju (26.3%) and Seoul (48.8%). Because GAS is very common, highly contagious and cause fatal infections, bacteriological and epidemiologic studies on GAS infections should be continued. With resurgence of rheumatic fever in developed countries, the increasing incidence of PSGN in Chinju area may indicate the need of national surveillance program.