Antibiotic concentration in pancreas tissue is very important for the treatment of severe acute pancreatitis (SAP) with infection. We report a case of a 44-year-old female with SAP on treatment of vancomycin. The time courses of vancomycin concentration in serum and pancreas tissue of the patient was described. This case demonstrated that it took about 30 minutes for vancomycin to get through from serum to pancreas tissue and about 76% of vancomycin could move into pancreas tissue for SAP patients.