Background and Aims Synchronous double primary hepatocellular carcinoma and intrahepatic cholangiocarcinoma (sdpHCC-ICC) is extremely rare. Here, the authors report the diagnosis and treatment process of 9 cases of sdpHCC-ICC, and investigate the clinical characteristics and post-operative prognosis of this condition, so as to raise clinical awareness.Methods The clinical data of 9 patients with sdpHCC-ICC (as confirmed by postoperative pathology) treated in the Fifth Medical Center of Chinese PLA General Hospital between January 2016 and December 2022 were retrospectively collected. The clinical manifestations, pathogenesis, imaging features, pathological characteristics, treatment strategy, and prognosis were evaluated.Results All patients were male with a history of chronic hepatitis, including 8 patients infected with hepatitis B, 7 patients with long-term alcohol consumption, 2 patients with elevated hepatocellular carcinoma and intrahepatic cholangiocarcinoma markers. Preoperative imaging examinations failed to make the correct diagnosis in all patients. All patients received surgical treatment and were identified as sdpHCC-ICC by postoperative pathological diagnosis. The intrahepatic lesions in 6 patients simultaneously expressed CD34. The postoperative follow-up was conducted for 2 to 58 months, relapse occurred in 2 patients on 6 and 20 months after operation, respectively, and no relapse occurred in the other 7 patients as of this manuscript writing.Conclusion The tumor cells of sdpHCC-ICC have different origins, which can be a monoclonal or multiclonal origin. Long-term alcohol consumption may be one of the risk factors. Surgical resection is still an effective treatment. The tumor stage of the intrahepatic cholangiocarcinoma components is one of the main factors affecting the prognosis of surgery. Lymph node dissection should be included in the surgical plan. Transcatheter arterial chemoembolization is effective for HCC components.