Comparison of the 16S rDNA sequence of Pseudomonas antimicrobica LMG 18920T with published 16S rDNA sequences from other pseudomonads indicated that Pseudomonas antimicrobica belongs to the genus Burkholderia, with Burkholderia gladioli, Burkholderia glumae and Burkholderia plantarii as its closest neighbours. DNA-DNA hybridizations confirmed that Pseudomonas antimicrobica and Burkholderia gladioli represent the same species. Strain LMG 18920T and other Burkholderia gladioli strains were also indistinguishable by SDS-PAGE of whole-cell proteins and had similar biochemical characteristics. The whole-cell fatty acid composition, however, was different from that of other Burkholderia gladioli strains. It is concluded that Pseudomonas antimicrobica is a later synonym of Burkholderia gladioli. As Burkholderia gladioli is known to cause infections in patients with cystic fibrosis and chronic granulomatous disease, the eventual use of strain LMG 18920T as a biological control agent should be approached with caution.