Hypothesis: Primary intrahepatic lithiasis occurs frequently in East Asia but is rare in Western countries. Biliary pain and episodes of cholangitis are the most common presenting symptoms, whereas intrahepatic cholangiocarcinoma represents a long-term unfavorable complication of the disease. When a single liver lobe or segment is involved, partial hepatectomy may be regarded today as an effective method of treatment., Design: Retrospective study., Setting: Hepatobiliary unit in a tertiary care hospital., Patients: The clinical records of 35 patients treated for primary intrahepatic lithiasis between January 1, 1992, and December 31, 2005, were reviewed and clinical data, cholangiograms, operative procedures, and early and late results were examined., Interventions: Thirty-four patients underwent liver resection; left hepatectomy (18 patients) and left lateral segmentectomy (10 patients) were the most frequently performed procedures. A cholangiocarcinoma was found in 3 patients (8.6%): 2 underwent liver resection and 1, who was found unresectable at surgery, underwent only explorative laparotomy., Main Outcome Measures: Survival, quality of life, laboratory data, and need for further treatments., Results: There was no postoperative mortality. Morbidity was 20.0% with a prevalence of infectious complications related to bile leakage. Long-term results, assessed in 26 patients with follow-up longer than 12 months (range, 12-170 months; mean, 63 months), were good or fair in 24 patients (92.3%), including 3 patients who needed subsequent endoscopic removal of biliary stones., Conclusions: Primary intrahepatic lithiasis more commonly involves 1 single liver segment or lobe. Partial hepatectomy is a safe and effective procedure, allowing definitive treatment of the disease and prevention of cancer.