Primary sclerosing cholangitis (PSC) is a rare but clinically significant hepatobiliary complication of ulcerative colitis (UC), associated with complex biliary strictures and recurrent obstruction that can require advanced endoscopic assessment. In PSC–UC phenotype, multifocal strictures impair bile drainage and promote secondary intrahepatic stone formation, which may complicate ductal clearance with conventional ERCP. We present a long-term PSC–UC case illustrating the role of cholangioscopy in achieving effective management of recurrent intrahepatic obstruction that had persisted despite multiple ERCP interventions. A young woman with history of UC diagnosed in 2006, in overall sustained clinical and endoscopic remission aside from a single postpartum flare, presented in 2024 with symptoms of acute cholangitis. MRCP revealed multifocal intrahepatic strictures with a beaded configuration, along with multiple stones predominantly involving the left ducts, consistent with PSC. Initial endoscopic management achieved extraction of common bile duct stones using standard techniques, although a markedly dilated left intrahepatic duct with residual lithiasis and inflammatory stricturing persisted, limiting adequate drainage and prompting interval cross-sectional reassessment. Later that year, the patient experienced a second clinically significant episode of cholangitis, again requiring ERCP with only partial clearance of intrahepatic lithiasis. In 2025, MRCP demonstrated progressive disease evolution, with marked dilation of the left intrahepatic ducts and an infiltrative-appearing dominant stenosis at the hepatic confluence, warranting further evaluation to exclude malignancy. These findings supported the use of SpyGlass cholangioscopy to enable comprehensive intraductal inspection, lithotripsy-assisted stone retrieval and targeted biopsy of the stenotic segment. The stricture appeared inflammatory on direct inspection and was subsequently confirmed as non-malignant by histopathological report. Cholangioscopy allowed complete clearance of impacted left intrahepatic stones, direct evaluation of multifocal inflammatory strictures, and targeted biopsies confirming non-malignant disease, thereby restoring effective segmental ductal decompression. The intervention was completed without procedure-related complications. Follow-up imaging confirmed sustained improvement in left-sided biliary drainage, with complete clinical resolution and no recurrence of cholangitic symptoms. Cholangioscopy provided decisive diagnostic and therapeutic benefit in PSC–UC with complex intrahepatic obstruction, achieving complete ductal clearance and accurate intraductal tissue evaluation. This procedure demonstrates particular value when conventional ERCP alone fails to achieve adequate ductal evaluation or complete therapeutic management.