Introduction : The coexistence of two primary malignant tumors is very rare. Multiple primary malignant neoplasms were first described by Billroth in 1889. Mongolia has the highest HCC incidence in the world with 93.7, followed by EGYPT. The number one cause of cancer-related death was the HCC, responsible for 44% of male and 42% of female cancer deaths.

Methods : Case report. A 56-year-old, female patient was admitted to the General Surgery Department of the Second General Hospital of Mongolia in September 2019, presenting with abdominal discomfort and fatigue for the last 2 weeks. There was history of positive HBV and no HCV infection and no over usage of alcohol, no remarkable family history. The Right hepatectomy plus right nephrectomy preserving the right adrenal gland. The laparotomy performed by the right Makuuchi incision, the liver resection was done by the Glissonean approach with 10 minutes of Pringle maneuver and Kelly clamping technique.

Results : The surgery was successful within 3 hours, with 200 ml of blood loss. After surgery, the patient was admitted to the ICU for close monitoring. We did not experience the kidney or liver failure after surgery. The patient was discharged on POD 7 with no complication.

Conclusions : We have experienced a very rare case of synchronous primary cancers of the liver and kidney. There are many case reports of diagnoses and treatment of multiple alimentary tract primary cancers, but there are a few reports of their recurrence and survival. We have to describe the character of malignancy.