Among Pseudomonas strains isolated from Korean agricultural soils, four strains (Ps 9-14 group: Ps 1-2, Ps 1-10, Ps 5-5 and Ps 9-14T) from the Suwon, Goesan and Samchok regions, three strains (Ps 3-10 group: Ps 2-22, Ps 3-1 and Ps 3-10T) from Umsong Region and four strains (Pss 26 group: Pss 14, Pss 25, Pss 26T and Pss 27) from Jinju Region were identified as three independent groups on the basis of 16S rDNA sequence analysis. While, on the basis of 16S rDNA sequence analysis, Ps 9-14T and Ps 3-10T form a phyletic line with Pseudomonas jessenii CIP 105274T, 'Pseudomonas pavonaceae' IAM 1155 and Pseudomonas graminis DSM 11363T, Pss 26T is grouped with Pseudomonas citronellolis ATCC 13674T and Pseudomonas nitroreducens IAM 1439T. According to DNA-DNA hybridization studies, strain Ps 9-14T shows high DNA relatedness to strain Ps 3-10T (52%) and Pseudomonas migulae CIP 105470T (49%) and strain Ps 3-10T reveals high relatedness to strain Ps 9-14T (48%) and P. jessenii CIP 105274T (45%). Strain Pss 26T shows high relatedness to P. citronellolis LMG 18378T (54%), P. nitroreducens ATCC 33634T (48%) and Pseudomonas aeruginosa LMG 1242T (48%). On the basis of phenotypic and genotypic analyses, three novel species of the genus Pseudomonas are proposed: Pseudomonas koreensis sp. nov. (type strain Ps 9-14T =LMG 21318T =KACC 10848T) for the Ps 9-14 group, Pseudomonas umsongensis sp. nov. (type strain Ps 3-10T =LMG 21317T =KACC 10847T) for the Ps 3-10 group and Pseudomonas jinjuensis sp. nov. (type strain Pss 26T =LMG 21316T =KACC 10760T) for the Pss 26 group.