Primary lymphoma of the common bile duct is an extremely rare disease. Only two detailed case reports have been published in the literature. In the present paper, a 68-year-old female with obstructive jaundice and a primary lymphoma of the common bile duct, which was resected, is described in detail because of the rarity of the lesion in the literature. The cholangiogram demonstrated stricture of the common bile duct. The findings at angiography and computed tomography were non-specific, but a hypo-echoic mass filling the lumen of the bile duct was demonstrated by ultrasonography. Subtotal resection of the common bile duct and cholecystectomy was performed as the method of choice, although the frozen section examination was not definitive. The final histological diagnosis was malignant lymphoma of the diffuse, small cleaved cell type. There was no metastasis to dissected regional lymph nodes. External irradiation was effective when recurrent tumors were found six months later. However, the patient developed generalized disease one year after resection. Although combination chemotherapy was effective this time for her lymphadenopathy, she died of pneumonia one year and four months after surgery. It can be postulated that ultrasound would be useful in diagnosing this rare entity, and that adjunctive radiotherapy after resection would be preferable to prevent progression of the disease.