Fine needle aspiration of pancreatic fluid collections. The complications of pancreatitis remain diagnostic and therapeutic challenges. Patients with simple pancreatitis, pancreatic necrosis, pseudocyst, noninfected fluid collection or abscess may all have similar clinical pictures. During the last decade computerized tomography (CT)-guided needle aspiration of peripancreatic fluid collections has been increasingly used as a diagnostic tool for pancreatic abscesses. This study reviewed the effectiveness of CT-guided needle aspiration of peripancreatic fluid collections at our institution in terms of diagnostic accuracy, correlation with eventual outcome, and safety. Charts of patients who underwent needle aspiration of de novo peripancreatic fluid collections over the past 2 years were reviewed. Thirty-five patients underwent 50 aspirations. Eleven patients (31%) had a positive aspirate culture; seven of these had a positive Gram's stain. There were no false positive Gram's stains but four false negatives. Twenty-four (69%) patients had negative aspirate Gram's stains and cultures. Patients with positive aspirate cultures were treated with antibiotics only (2), CT-guided drain placement (7), or surgical drainage (3). The mortality related to each of these therapeutic modalities was 50 per cent, 0 per cent, and 33 per cent, respectively. Of the 24 patients with negative aspirate cultures, five had no further treatment, 12 received antibiotics, and six underwent CT drain placement. All these patients survived. There was one false negative aspirate culture. This patient underwent delayed surgical drainage but expired. There were no major complications from CT-guided aspiration. CT-guided aspiration appears to be a safe and reliable method of diagnosing infection in peripancreatic fluid collections. 