Background: The cause of post-cholecystectomy syndrome can be classified as a biliary or non-biliary source from the stomach, esophagus, pancreas and blood vessels. Remnant gall bladder stone or cystic duct stone is an important cause of biliary PCS. This study deals with cystic duct stump stone, as a cause of PCS. Materials &Methods: The study was conducted in Erbil teaching hospital in Erbil/Iraq, from second January 2012 to 15th February 2020. Twelve female patients who had cystic duct stones were included in the study. The cystic structure containing stones confirmed by ultrasound and MRCP examinations. Laparoscopic completion surgery done. Results: Patients with PCS presented at variable interval ranging from two weeks to two years after cholecystectomy. The mean age of patients was 43.33±7.18, the youngest patient was 35 years old while the oldest was 56 years old. The presenting symptom was colicky right upper abdominal pain in 10 patients (83.3%), the other two patients presented with features similar to cholecystitis. All the twelve patients underwent re-exploration by Laparoscopy successfully without conversion to open surgery. The mean operative time was 79.33±20.27 minutes. Conclusion: PCS in our study were probably from stone formation and impaction in the stump of the long remnant cystic duct, the obstruction caused by impacted stone made distal dilatation and cyst formation which was difficult to differentiate it from remnant gall bladder (after subtotal cholecystectomy). Laparoscopic completion surgery is preferable although need longer operation time.