Central venous catheters (CVCs) have become more common in the care of very low birthweight newborns. Nutrition is enhanced, fluid delivery is more secure, and stress from the intervention of starting new IVs is reduced. Complications of these devices include infection, thrombus or embolus, damage to vessels and organs, and extravascular collections of fluid. Pleural fluid collections can occur due to superior vena caval obstruction with obstruction of lymphatic drainage, and erosion or perforation of the catheter through the vein into the pleural space. Three infants weighing less than 1000 gm had CVCs placed in an antecubital vein. Severe respiratory compromise developed in 1 at 5, 1 at 6, and 1 at 40 hours after line placement, and chest radiograph suggested fluid in the right pleural space. Milky fluid was found in two cases in which the infants received lipid emulsion and parenteral nutrition fluid (PNF). Bright yellow fluid, resembling PNF, was found in the third, not receiving lipids. None of the patients was enterally fed. The tips of the CVCs were adjusted to a more peripheral location and there was no recurrence of pleural fluid, nor were signs of superior vena cava syndrome seen. Etiologies for the unilateral hydrothorax include vein perforation and erosion, but another cause is discussed. A right pleural fluid collection in a patient with a CVC tip in the right subclavian vein is a serious problem, which may be solved with repositioning of the CVC instead of removal.