A Gram-reaction-positive, motile, coccus-shaped actinobacterium, designated strain T2A-S27T, was isolated from a roof tile in Oporto (Portugal) and studied using a polyphasic approach. The 16S rRNA gene sequence of the novel isolate showed high similarity to that of Kineococcus marinus KST3-3T (97.8 % sequence similarity). Strain T2A-S27T showed lower 16S rRNA gene sequence similarities with other members of the genus Kineococcus and members of the family Kineosporiaceae (<94 %). A phylogenetic tree, based on 16S rRNA gene sequences, showed that strain T2A-S27T formed a coherent clade with the type strain of K. marinus and Quadrisphaera granulorum. The isolate was characterized by the presence of meso-diaminopimelic acid in the cell-wall peptidoglycan, MK-9(H2) as the predominant menaquinone and a polar lipid profile consisting of diphosphatidylglycerol and phosphatidylglycerol. The fatty acid profile was dominated by anteiso-C15 : 0. The DNA G+C content was 76.9 mol%. The low level of DNA–DNA relatedness to K. marinus (46–47 %) and the results of the chemotaxonomic and physiological studies clearly distinguished strain T2A-S27T from recognized species of the genus Kineococcus. On the basis of its phylogenetic position and phenotypic traits, strain T2A-S27T ( = LMG 24148T = CECT 7306T = DSM 23768T) represents a novel species of a new genus in the family Kineosporiaceae, for which the name Pseudokineococcus lusitanus gen. nov., sp. nov. is proposed. The misclassified species K. marinus is transferred to the new genus as Pseudokineococcus marinus comb. nov. The type strain of Pseudokineococcus marinus is KST3-3T ( = KCCM 42250T = NRRL B-24439T).