We report the case of a 52 year-old woman who was re-admitted to regular hemodialysis treatment because of chronic rejection of a renal transplant. She had received her mother's kidney 17 years before and had been treated for a long time with steroids, cyclosporin and azathioprine. In the last two months, fever had occurred, and persisted with the start of hemodialysis. She was admitted to our nephrology unit. Clinical, laboratory, radiological and endoscopic investigations did not lead to a precise diagnosis and broad-spectrum antimicrobial therapy failed. Some days later, a clear clinical picture of acute abdomen arose and at laparatomy a perforated jejunal ulcer was found. Histological investigation revealed caseous necrosis around the ulcer. Ziehl-Neelsen (ZN) stain showed a number of acid-fast resistant bacilli. Polymerase chain reaction (PCR) confirmed the presence of Mycobacterium tuberculosis. Specific therapy was started, but nevertheless the patient died a few days later, of septic shock. Our case shows that tuberculosis continues to be a significant, severe clinical problem in transplant recipients and is in fact still an important cause of death in these patients. The possibility of tuberculosis must be taken into account when a transplant patient shows fever and severe abdominal trouble with no clear evidence of another infection.