Right atrial electrocardiography has been used both for the positioning of ventriculoatrial shunts and for the detection and treatment of air embolism during neurosurgical procedures. Its use for the precise placement of central venous catheters for parenteral nutrition is described here. 50 lines were placed in 48 patients. The lines were satisfactorily sited in 48 cases. No false-negative or false-positive traces were obtained. The technique is extremely accurate; failure to obtain the characteristic traces indicates malposition of the catheter tip. The need for on-table radiography is virtually eliminated.