BACKGROUND: Thus far, seven cases of Arthrobacter woluwensis (A. woluwensis) infections have been reported globally. Its rarity and overlapping characteristics with other bacterial species make identification challenging, necessitating 16S ribosomal RNA sequencing and whole-genome sequencing. METHODS: For the first time, A. woluwensis bacteremia was diagnosed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). RESULTS: The isolated A. woluwensis was susceptible to vancomycin. A. woluwensis bacteremia was resolved with the administration of intravenous vancomycin and the removal of the chemoport. CONCLUSIONS: MALDI-TOF MS can be useful in diagnosing A. woluwensis infections.