SummaryEighteen cases of pneumococcal pneumopathies with septicemia are proposed. Bacteriological diagnosis was made by blood rather than sputum cultures.Strictly anaerobic pneumococci were discovered and a study was made of their properties (physical charactéristics ?) (paleopneumoniae ?). Nine cases involved numerous complications, while three were fatal, despite appropriate antibiotherapy (elderly patients, poor physical status, septic metastases, secondary hospital-born infections).