Four Gram-positive-staining, microaerophilic, non-spore-forming, fructose-6-phosphate phosphoketolase-positive bacterial strains were isolated from a faecal sample of a 5-year-old ring-tailed lemur (Lemur catta). The strains showed a peculiar morphology, resembling a small coiled snake, a ring shape, or forming a little ‘Y’ shape. The isolated strains appeared identical, and LMC 13^T was chosen as a representative strain and characterized further. Strain LMC 13^T showed an A3β peptidoglycan type, similar to that found in Bifidobacterium longum . The DNA base composition was 57.2 mol% G+C. Almost-complete 16S rRNA, hsp60, rpoB, dnaJ, dnaG, purF, clpC and rpoC gene sequences were obtained, and phylogenetic relationships were determined. Comparative analysis of 16S rRNA gene sequences showed that strain LMC 13^T showed the highest similarity to B. longum subsp. suis ATCC 27533^T (96.65 %) and Bifidobacterium saguini DSM 23967^T (96.64 %). Strain LMC 13^T was located in an actinobacterial cluster and was more closely related to the genus Bifidobacterium than to other genera in the Bifidobacteriaceae . On the basis of these results, strain LMC 13^T represents a novel species within the genus Bifidobacterium , for which the name Bifidobacterium lemurum sp. nov. is proposed; the type strain is LMC 13^T ( = DSM 28807^T = JCM 30168^T).