Primary pancreatic lymphoma (PPL) is a very rare disease. We report five cases of PPL (4 men and 1 woman, mean age 65 years) diagnosed and treated at our Institution from 1987 to 1997. None of these patients had evidence of extrapancreatic disease and they were categorized as PPL involving pancreas only (stage IE, 3 patients) or pancreas and peripancreatic lymph nodes (stage IIE, 2 patients). The most common presenting symptoms were abdominal pain and weight loss. Imaging techniques showed a mass of the pancreatic head in all cases. The histological diagnosis (3 diffuse-large cell non-Hodgkin's lymphoma and 2 lymphoplasmacytic lymphoma/immunocytoma) was made by ultrasound-guided fine needle aspiration biopsy and tissue core fine-needle biopsy in three patients and by surgery in the remaining two patients. The three patients diagnosed by percutaneous biopsy were treated with chemotherapy as front-line therapy and two of them received also local radiotherapy; one of these patients is still alive in complete remission at 69 months, one died of an unrelated disease at 67 months and one died of lymphoma relapse at 88 months. Two patients underwent pancreaticoduodenectomy plus adjuvant chemotherapy; one of them died of recurrent cholangitis 8 months after surgery while the other one is still alive in complete remission after 160 months. This study shows that: 1) imaging techniques can suggest the suspicion of PPL but are unable to distinguish PPL from pancreatic adenocarcinoma; 2) histological diagnosis can be easily obtained by percutaneous US-guided tissue core biopsy; 3) surgery can be avoided both for diagnosis and therapy but the treatment of choice of PPL may only be evaluated on a larger series of patients.