From August 1991 to July 1992 11 microbiological institutes in the Federal Republic of Germany and two in Austria registered 4380 episodes of septicaemia with 4603 microorganisms isolated. The results regarding sex, age, type of hospital, type of referring specialty, type of hospital unit and the spectrum of causative organisms were compared with similar data collected 7 years previously over a period of 2 years for 8500 septicaemia episodes involving 8999 microorganisms by 13 German and two Austrian institutes. The spectrum of causative organisms differed between the two studies: a doubling in the incidence of pneumococci from 2.5 to 5%, an increase of enteritis Salmonella from 1.1 to 1.8%, and a decrease of Haemophilus influenzae from 0.9 to 0.5%. Among newborns in the first 3 weeks of life the incidence of B-streptococci increased from 14.2 to 21.5%, while that of A-streptococci among medical patients increased from 20.6 to 38.3%. An analysis of clinical data revealed nonhemolytic streptococci as the most frequent causative organism in endocarditis (32.5%); pneumococci and staphylococci (26.6 and 22.1%, respectively) in pulmonary infections; gram-negative rods in urinary tract infections (77.9%); gram-negative rods and coagulase-negative staphylococci in leukaemia (46.9 and 18%); and staphylococci with 61% in septicaemia due to intravascular foreign bodies.