Summary. Because of increasingly frequent infection rates bacteriologic problems represent a crucial point in the whole field of intensive care. Reasons of higher infection rates are the growing involvement of extremely young and older age groups, the increasing number of high risk operations, immunosuppressive therapy, contamination of equipment, as well as of intravenous and urinary catheters, and resistance to antibiotics.Especially endangered by infections are patients with tracheostomy, after prolonged intubation and longterm respirator therapy. A two-years study turned out, that in our own group of patients a continuous increase of infections with gramnegative bacteria--mainly Klebsiella and Aerobacter--was to be observed. By means of typical examples the most important sources of infection and the way of contamination are demonstrated. Consequently bacteriologic controls (according to the method of Kanz) and hygienic precautions have to be carried out repeatedly and adequatly. Desinfection of the hands for restriction of cross-infections is of outstanding importance.In addition a new, decentralized automatic bed desinfcction system is shown and the advantage in contrast to a central "bed station" is printed out.Hygienic requirement to be postulated for intensive care units have to include a control and supervision program with own personal, a clinical-bacteriological laboratory, adequate sterilization and desinfection facilities, extremely aseptic handling of indwelling cava-and urinary katheters, strict isolation of infected, mainly tracheostomized patients under artificial respiration, critical application of antibiotics and repeated training of medical and nursing personal.Zusammen]assung. Hygienisch-bakteriologische Probleme stellen in Anbetracht allgemein zunehmender Infektraten einen Schwerpunkt in der Gesamtproblematik der Intensivbehandlung dar. Ursachen hSherer Infektraten sind Zunahmen der extremen Altersklassen, der schweren Operationen, der immunsuppressiven Therapie, der Kontamination von Ger/iten sowie intraven6se und Blasen-Dauerkatheter und Antibioticaresistenz.Eine besondere Infektgef/ihrdung besteht bei tracheotomierten, prolongiert intubierten und langzeitbeatmeten Patienten.Eine Zweijahresstudie zeigt, dab Infektionen mit gramnegativen Erregern --im eigenen Krankengut stehen Klebsiella/Aerobacter an der Spitze --st~ndig zunehmen. Anhand von Beispielen werden die wichtigsten Infektionsquellen und -wege aufgezeigt. Als Konsequenz m/issen bakteriologische Kontrollen (mit Hilfe der Abklatschmethode nach Kanz) und hygienische Mallnahmen regelmgllig und ad/~quat durchgeffihrt werden. Die H/~ndedesinfektion zur Eind/immung der Kreuzinfektion ist von zentraler Bedeutung. 35 Langenbecks Arch. Chit., Bd. 332 (Kongrel3bericht 1972)