A polyphasic taxonomic study, using phenotypic, phylogenetic and genotypic characterization, was performed on five Gram-stain-positive, catalase-negative, coccus-shaped Vagococcus-like bacteria isolated from the spoilage microbiota of cooked shrimp. Comparative 16S rRNA gene sequence analysis indicated that the isolates belonged to the genus Vagococcus. The five isolates shared 100% 16S rRNA gene sequence similarity, and representative strain CD276(T) formed a branch that was distinct from the type strains of the six recognized species of the genus Vagococcus (Vagococcus fluvialis CCUG 32704(T), V. salmoninarum NCFB 2777(T), V. lutrae CCUG 39187(T), V. fessus M2661/98/1(T), V. carniphilus ATCC BAA-340(T) and V. elongatus PPC9(T)). The taxonomic position of strain CD276(T) was clarified using DNA-DNA hybridization, pulsed-field gel electrophoresis of whole-genome DNA, G+C content determination, cell-wall peptidoglycan typing, fatty acid analysis and biochemical characterization. On the basis of this evidence, a novel species, Vagococcus penaei sp. nov., is proposed. The type strain is CD276(T) (=LMG 24833(T) =CIP 109914(T)).