Bacteremia caused by Eggerthia catenaformis is a rarely reported pathogen in cancer patients. Herein, we report a case of bacteremia caused by E.catenaformis in a patient with gastric cancer in China. The patient was a 55-year-old man, diagnosed with gastric cancer more than one month ago, with intermittent fever at a maximum of 39.5 °C for more than half a month. He received symptomatic and supportive treatment after admission to our hospital; a rare anaerobic microorganism, E. catenaformis was isolated from an anaerobic blood culture sample taken from the patient. The antimicrobial susceptibility testing was performed after the isolates were successfully identified by MALDI-TOF MS and 16S rRNA sequencing. The patient was then successfully treated for the bacteremia with metronidazole. To the best of our knowledge, this is the first report of E. catenaformis bacteremia in a patient with cancer.