A bacterial strain, designated Ch-32(T), was isolated from the phyllosphere of Castanea sativa in Spain. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolate in the genus Paenibacillus within the same subgroup as Paenibacillus xinjiangensis and Paenibacillus glycanilyticus, with similarities of 96.3 and 96.8 %, respectively. DNA-DNA hybridization values for strain Ch-32(T) with these two species were lower than 20 %. The novel isolate was a Gram-variable, motile, sporulating rod. It produced catalase and oxidase and hydrolysed cellulose, gelatin and aesculin. Acetoin and urease production, nitrate reduction and starch hydrolysis were negative. Growth was supported by many carbohydrates and organic acids as carbon sources. MK-7 was the only menaquinone detected and anteiso-C(15 : 0), iso-C(16 : 0) and C(16 : 0) were the major fatty acids. The DNA G+C content was 46 mol%. Phylogenetic, DNA relatedness and phenotypic analyses showed that strain Ch-32(T) should be classified as a novel species of the genus Paenibacillus, for which the name Paenibacillus castaneae sp. nov. is proposed; the type strain is Ch-32(T) (=CECT 7279(T)=DSM 19417(T)).