Sarcina ventriculi (S. ventriculi), a gram-positive, non-spore-forming and non-motile anaerobic coccus, was discovered and named by John Goodsir in 1842 [1]. Under an optical microscope, eight bacteria can usually be seen stacked in a cubic shape [2]. S. ventriculi can adapt well to changes in pH conditions. Under acidic pH conditions, it grows vigorously and exhibits a square or rectangular cell arrangement; In alkaline pH environment, it forms spores that can survive for years [3]. S. ventriculi infection has been associated with various gastrointestinal diseases, ranging from asymptomatic presentations to acute abdomen due to gastric perforation, with various forms of gastritis being the most common [4]. However, bloodstream infections caused by S. ventriculi are rarely reported [5]. Herein, we report a case of a patient with advanced sigmoid colon adenocarcinoma who underwent multiple rounds of chemotherapy and radiotherapy. Unfortunately, the patient developed S. ventriculi bloodstream infection, which progressed to septic shock and resulted the patient's death.