Purpose: Mirizzi syndrome is a rare complication of cholelithiasis that poses significant surgical and endoscopic challenges due to distorted biliary anatomy. Large impacted cystic duct stones are often refractory to standard endoscopic retrograde cholangiopancreatography (ERCP). We describe the use of SpyGlassTM-guided holmium laser lithotripsy as an adjunct to surgical management and report a novel Australian experience. Case: A 32-year-old female presented with jaundice and upper abdominal pain on a background of cholelithiasis. Initial ERCP raised concern for a choledochal cyst; however, further imaging demonstrated multiple cystic duct stones causing extrinsic compression of the common hepatic duct, consistent with Mirizzi syndrome. Following deterioration with acute cholecystitis, an emergency laparoscopic cholecystectomy was performed. Severe distortion of biliary anatomy necessitated a subtotal approach. Intraoperative cholangiography confirmed multiple large cystic duct calculi, two of which were retrieved. Definitive management of the residual stone was deferred to interval ERCP. Cholangioscopy using the SpyGlassTM system enabled direct visualisation of an impacted 20-mm cystic duct stone, which was treated with holmium laser lithotripsy. Staged ERCPs were performed to achieve complete ductal clearance. Results: SpyGlassTM-guided holmium laser lithotripsy successfully fragmented the impacted cystic duct calculus, allowing removal of residual fragments on follow-up ERCPs. Complete ductal clearance was achieved without biliary injury or further surgical intervention. Conclusion: SpyGlassTM-guided holmium laser lithotripsy is a safe and effective minimally invasive adjunct for managing impacted cystic duct stones in Mirizzi syndrome when conventional techniques are limited. This case represents, to our knowledge, the first reported Australian experience and supports broader use of advanced cholangioscopy in complex biliary disease.