Mycoplasma infections have extrapulmonary manifestations that may be associated with respiratory symptoms and may have skin, heart, gastrointestinal, rheumatologic, neurologic, hematologic involvement. Cold agglutinin mediated autoimmune hemolytic anemia is the most common hematological manifestation. We report a 27 years old woman infected with Mycoplasma pneumoniae, who presented respiratory involvement with pneumonia, exanthema, serositis and acute hemolytic anemia that required transfusion. The key for the diagnosis were the extrapulmonary manifestations associated with respiratory involvement after five days of hospitalization.Mycoplasma infections have extrapulmonary manifestations that may be associated with respiratory symptoms and may have skin, heart, gastrointestinal, rheumatologic, neurologic, hematologic involvement. Cold agglutinin mediated autoimmune hemolytic anemia is the most common hematological manifestation. We report a 27 years old woman infected with Mycoplasma pneumoniae, who presented respiratory involvement with pneumonia, exanthema, serositis and acute hemolytic anemia that required transfusion. The key for the diagnosis were the extrapulmonary manifestations associated with respiratory involvement after five days of hospitalization.