The published descriptions of Klebsiella planticola Bagley, Seidler, and Brenner 1982 and Klebsiella trevisanii Ferragut, Izard, Gavini, Kersters, De Ley, and Leclerc 1983 are very similar. The reactions given by the type strains of K. planticola and K. trevisanii were identical when these strains were submitted to 51 common tests and in 118 of 119 nutritional tests. The level of deoxyribonucleic acid relatedness between the two type strains was 79 to 94% (nitrocellulose filter method) or 70 to 104% (S1 nuclease method) depending on which deoxyribonucleic acid was tritium labeled. Heteroduplexes showed a thermal stability very close to that of homoduplexes. Thus, K. planticola and K. trevisanii are subjective synonyms. Since K. planticola has priority over K. trevisanii, K. planticola should be the only name used to refer to the species formerly designated K. planticola or K. trevisanii.