Biochemical and molecular genetic studies were performed on an unknown Gram-stain-positive, catalase-negative, coccus-shaped organism isolated from clinical samples of a Pyrenean chamois. The micro-organism was identified as a streptococcal species based on its cellular morphological and biochemical tests. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus, but the organism did not correspond to any species of this genus. The nearest phylogenetic relative of the unknown coccus from chamois was Streptococcus ovis (95.9 % 16S rRNA gene sequence similarity). The rpoB and sodA sequence analysis showed sequence similarity values of less than 85.7 % and 83.0 %, respectively, with the currently recognized species of the genus Streptococcus. The novel bacterial isolate was distinguished from S. ovis and other species of the genus Streptococcus using biochemical tests. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as a novel species of the genus Streptococcus, Streptococcus rupicaprae sp. nov., with the type strain 2777-2-07(T) ( = CECT 7718(T) = CCUG 59652(T)).