Central venous catheterization has become an important aid in the correct management of the critically ill patient and is being used more often than in the past. However, no technic of cannulation has been entirely free of complications. A needle which is inserted properly and positioned in the vein is not likely to produce complications arising from injury to adjacent structures; hence accurate knowledge of their anatomic relations is essential for central venous catheterization. We have experienced a case of hydrohemothorax as a complication of subclavian vein catheterization. We report this case with a review of the literature of central venous cathetherization and its possible complications.