Abstract Ultrasonography was used to diagnose, localize and direct the percutaneous transabdominal needle aspiration of 10 pancreatic pseudocysts in 9 patients. Thirty-four aspirations were performed without complication. In 9 pseudocysts no other treatment was necessary, and in all patients relief of pain or obstructive symptoms when present was obtained. None of the cysts have recurred with a mean follow-up of 26 months.