In this case, catheter-related bacteremia due to Globicatella sanguinis in a 43 years old female patient undergoing hemodialysis with the diagnosis of diabetic nephropathy was presented and the methods in the laboratory diagnosis of the rare opportunistic pathogen, Globicatella cins, were nvestigated. A set of peripheral blood cultures and simultaneous catheter culture was obtained from the patient in third of May 2016. Biochemical tests, Phoenix (Becton Dickinson, USA) and MicroScan (Beckman Coulter, USA) automated systems and matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF MS) based Microflex MS (Bruker, Daltonics, Germany) and VITEK MS (database v2.0) (bioMerieux, France) systems were used for the identification of the cultured bacteria. Partial 16S rDNA sequencing was done by using specific p8FPL 5'-AGT TTG ATC ATG GCT CAG-3' and p806R 5'-GGA CTA CCA GGG TAT CTA AT-3' primers. Minimal inhibitory concentrations (MICs) for vancomycin, erythromycin, imipenem, cefotaxime and benzypenicillin were determined by agar gradient method. The blood and catheter cultures yielded the same type of bacterial colonies. Alfa-hemolytic, catalase negative colonies observed on blood agar plates after an over night incubation yielded gram-positive cocci on Gram staining. In Sisli Hamidiye Etfal Hospital, the isolate was identifed as G. sulfidifaciens (score value > 2) by Bruker MS system and as G. sanguinis by Phoenix automated system. In Inonu University, the isolate could not be identified by Microscan automated system while VITEK MS named the isolate as 99.9% G. sanguinis and 98.3% G. sulfidifaciens. The 16S rDNA sequencing identifed the isolate as 100% G. sanguinis (GenBank accessionno. KJ680157.1). The MIC values were 0.38 mu g/ml, 1.5 mu g/ml, 0.38 mu g/ ml, > 32 mu g/ml and 64 mu g/ml for vancomycin, eryrthromycin, imipenem, cefotaxime and benzylpenicillin, respectively. The patient was diagnosed as catheter-related bacteremia and vancomycin (1 x 1 g IV/72 h) was used for up to 10 days. No fever and bacterial growth in cultures were present in her control visits. As G. sanguinis is not among the commonly encountered pathogens and due to difficulties in laboratory diagnosis, it may be missedor mis-identified in clinical laboratories. BD Phoenix and Bruker MS data bases lack G. sulfidifaciens and G. sanguinis, respectively, while the Globicatella genus is not present in MicroScan database. The increased number of medical implementations and the increasing number of immunosuppressed patient populations in recenty ears will lead to the emergence of rare bacteria. Increasing the diagnostic power of clinical microbiology laboratories by conventional and molecular methods and renewal of the databases of commercial identification systems by expanding the pathogen spectrum are significantly important for the prevention and control of infections caused by these agents.