A total of 88 environmental Klebsiella pneumoniae and K. oxytoca isolates were typed according to their bacteriocin susceptibility patterns. Bacteriocin typing was performed by a modification of the scrape-and-point method, using a set of 8 producer strains. This method proved to be very applicable to environmental strains of both species; all but one strain could be typed. Twenty-one different patterns were observed. Type 1-3456-8 was most common in both species. In contrast to K. pneumoniae, more than half of the K. oxytoca strains fell into only two bacteriocin susceptibility patterns. Bacteriocin types 1 and 3 showed a very broad spectrum, more than 95% of the isolates being sensitive to one of these bacteriocins.