Lactobacillusparacaseiis a gram-positive rod commonly found in probiotic foods and is well known to promote healthy gastrointestinal tracts. However, there have been a few case reports that have foundLactobacillus paracaseito be the causative agent in complications such as endocarditis, meningitis, peritonitis, pancreatitis, and cholecystitis.We present the case of a 76-year-old woman who was admitted for decompensated heart failure. The patient also reported abdominal pain in the right upper quadrant. Ultrasound findings suggested cholelithiasis and a subsequent hepatobiliary iminodiacetic acid (HIDA) scan confirmed acute cholecystitis. This patient was not a good candidate for cholecystectomy because of the risk of cardiac complications. Hence, percutaneous cholecystostomy tube (PCT) placement was done, and the aspirate drained during the procedure was sent for pathology. This bile culture was positive forLactobacillus paracaseiand negative for any other kinds of bacteria.The incidence ofLactobacillusspecies-induced cholecystitis makes up only 0.08% to 0.2% of cases, which makes this an unusual case of acute cholecystitis caused byLactobacillus paracasei. We will discuss several pathogenic aspects ofLactobacillus paracasei,such as its ability to generate biofilms, pore-forming toxins, drug transporters, and antibiotic susceptibility.