In a three-year survey conducted from 1988 to 1990 Klebsiella isolates from human clinical specimens were subjected to additional tests to identify any Klebsiella terrigena strains. Ten strains of Klebsiella terrigena (0.4%) were found among 2355 indole-negative Klebsiella isolates. Most of the isolates were recovered from the respiratory tract. In the API20EC system almost exclusively biotypes no. 1777771 and 1777671 were observed. Serotyping revealed capsule types K2, K5 and K18 in two strains each. In antibiotic susceptibility tests the strains were shown to be comparable in sensitivity to Klebsiella pneumoniae.