Primary pancreatic lymphoma (PPL) is an extremely rare disease, with few cases reported in literature. Clinical manifestations are usually nonspecific and mimic other pancreatic diseases. Owing to paucity of data and experience of PPL, clinico-pathological features, differential diagnosis, optimal treatment and overall outcomes are not well known. Varicella zoster virus (VZV) is known to cause varicella in children and herpes zoster in adults. Acute pancreatitis caused by VZV is a rare and serious complication, with immunocompromised individuals being primarily affected. We report a case of VZV associated acute pancreatitis in a patient who was diagnosed and treated for primary pancreatic lymphoma, thus rendering her immunocompromised and susceptible to developing infectious pancreatitis. A 56 year old female patient presented with recurrent vomiting, upper abdominal pain and hyperaesthesia in the right upper quadrant of 2 days duration. Following admission her right sided abdominal pain worsened (stabbing pain) and a diagnosis of acute pancreatitis was confirmed based on elevated serum amylase levels and CT scan findings of pancreatic enlargement. The patient was managed conservatively with intravenous fluids, antibiotics, analgesics and topical acyclovir ointment. The patient continues to be asymptomatic after 5 years of follow up. Though extremely rare, a diagnosis of herpes zoster pancreatitis should be considered in such patients, and prompt treatment initiated to prevent further deterioration and to minimize mortality. Core tip: Primary pancreatic lymphoma is in itself a very rare disease, and our patient having presented with herpes zoster associated acute pancreatitis in a background of PPL makes this case even rarer. This is probably the first case report of herpes zoster associated acute pancreatitis in an immunocompromised patient due to primary pancreatic lymphoma.