An 8.3-Fr modified pigtail catheter has been developed for chronic percutaneous drainage of pericardial effusions. Placement of this catheter using a modified Seldinger technique is virtually atraumatic. To test the safety and efficacy of this catheter for pleural drainage, it was used to manage eight collections of pleural fluid and nine pneumothoraces in a total of 12 infants and children. There were no placement complications. Fluid accumulations were satisfactorily drained in every instance. Pneumothoraces were treated definitively with a single catheter, except when a bronchopleural fistula was present. Percutaneous pigtail drainage of pleura fluid or air is simple, safe, effective, and substantially less traumatic than standard chest-tube placement.