Streptococcus pyogenes, which is classified to Group A streptococcus (GAS), is one of the most common bacterial pathogens of the childhood infection. This organism can cause acute bacterial pharyngitis, impetigo, peritonsilar abscess or scarlet fever. It can also cause severe invasive diseases such as toxic shock syndrome, sepsis, septic arthritis, necrotizing pneumonia or necrotizing fasciitis. Usually, invasive GAS infections are accompanied by systemic symptoms and signs. Necrotizing pneumonia presents with acute fever, pleuritic chest pain and cough. The progress of disease is usually rapid and typically, pleural effusion develops in the early course of disease. Necrotizing fasciitis is relatively rare but once it has developed, it may be life threatening and cause necrosis of adjacent soft tissues with rapid progress. Clinical manifestations of parapharyngeal abscess are fever, dysphagia or bulging of pharyngeal wall. We experienced three cases of GAS infections which were presented atypically.