Background and Aims Laparoscopic anatomical liver segmentectomy has been widely applied in the surgical treatment of hepatic tumors due to its safety, feasibility, and effectiveness. The combination of indocyanine green (ICG) fluorescence-guided positive staining and intraoperative laparoscopic ultrasound has become an important technique for precision liver resection, particularly in accurately delineating hepatic segment/subsegment boundaries and achieving negative surgical margins. This study reports a case of anatomical resection of the right posterior segment and the dorsal subsegment of the right anterior segment of the liver, guided by laparoscopic ultrasound combined with ICG positive staining, to evaluate its clinical feasibility and outcomes.Methods A retrospective analysis was conducted on an elderly female patient with a hepatic space-occupying lesion who underwent laparoscopic anatomical resection of the right posterior segment and right anterior dorsal subsegment using intraoperative ultrasound combined with ICG fluorescence-guided positive staining.Results Preoperative three-dimensional reconstruction revealed that the tumor was located in the right posterior segment and right anterior dorsal subsegment. Intraoperatively, under laparoscopic ultrasound guidance, the anterior-ventral branch of the right portal vein was punctured and injected with ICG to achieve precise staining of the right anterior-ventral subsegment. The resection was performed along the fluorescent boundary, enabling accurate anatomical removal of the targeted liver segments. Intraoperative blood loss was approximately 100 mL without transfusion. Pathology confirmed a moderately differentiated small-duct type intrahepatic cholangiocarcinoma with negative margins (R₀ resection). The patient recovered well and was discharged on postoperative day 19. Follow-up CT at 6 months showed no evidence of recurrence.Conclusion During anatomical resection of the right posterior segment and right anterior dorsal subsegment of the liver, laparoscopic ultrasound combined with ICG fluorescence-guided positive staining can accurately define segmental boundaries, enhance surgical safety, and ensure complete tumor resection, thus offering significant value in achieving R₀ resection.