Among a large collection of Taiwanese soil isolates, a novel Gram-variable, rod-shaped, motile and endospore-forming bacterial strain, designated G-soil-2-3(T), was isolated from farmland soil in Wu-Feng, Taiwan. The isolate was subjected to a polyphasic study including 16S rRNA gene sequence analysis, DNA-DNA hybridization experiments, fatty acid analysis and comparative phenotypic characterization. 16S rRNA gene sequence analysis indicated that the organism belongs within the genus Paenibacillus. It contained menaquinone MK-7 as the predominant isoprenoid quinone and anteiso-C(15 : 0) (40.5 %), iso-C(15 : 0) (13.1 %), iso-C(16 : 0) (10.8 %) and anteiso-C(17 : 0) (7.3 %) as the major fatty acids. Phylogenetically, the closest relatives of strain G-soil-2-3(T) were the type strains of Paenibacillus assamensis, Paenibacillus alvei and Paenibacillus apiarius, with 16S rRNA gene sequence similarity of 95.7, 95 and 95.2 %, respectively. DNA-DNA hybridization experiments showed levels of relatedness of 2.8-9.0 % of strain G-soil-2-3(T) with these strains. The G+C content of the DNA was 44.6 mol%. Strain G-soil-2-3(T) was clearly distinguishable from P. assamensis, P. alvei and P. apiarius and thus represents a novel species of the genus Paenibacillus, for which the name Paenibacillus taiwanensis sp. nov. is proposed. The type strain is G-soil-2-3(T) (=BCRC 17411(T)=IAM 15414(T)=LMG 23799(T)=DSM 18679(T)).