Background: Bacterial infection of gallbladder play a major role in 50 % of patients with cholelithiasis with or without gallstones and can be caused by any type of bacteria.Objectives: To show the role of Nanobacter species in chollangitis and cholelithiasis in patients with cholelithiasis. 
Patients and Methods: One hundred and five (105) fluid, stone, or both were taken from Patients with symptoms of cholecystitis and cholelithiasis. They were attending the Consultation Surgical Clinic at Ramadi General Hospital and Heet General Hospital during the period patients after cholecystectomy during the period from November 2019 to April 2020. Patients well examined and diagnosed by a senior surgeon,  Specimens of aspirated (fluid and stone) after cholecystectomy were taken from each patient, each stone specimen was preserved in brain heart infusion broth and then sent to the laboratory, in the laboratory each specimen was divided into two parts, one of them was incubated at 37ᛜC for 24 hours for bacteriological investigations and the other part stored at  -20C  for molecular study by polymerase chain reaction (PCR).Results: Out of a total of 105 investigated specimens, sixty-two (62,59.0%) specimens gave a positive bacterial culture, and the remaining 43, 41.0% were showing negative bacterial culture.  Sixty-two (62) bacterial isolates were isolated from positive culture specimens, including both Gram-positive and Gram-negative bacteria. Gram-positive bacteria found at resembled 15.2% and Gram-negative bacteria were found at a rate of 43.8%.
Conclusion: Meropenem, Imipenem, Levofloxacin, Amikacin, Nitrofurantoin and can be considered a drug of choice to treat Cholelithiasiswith sensitivity rate ,85.5%, 71.0%, 64.5%, 67.7%, 62.9% respectively.