Accurate positioning of the catheter tip is one of the most critical procedures in central venous catheter insertion. The traditional surface measurement method frequently has a large deviation and increases the X-ray exposure of doctors and patients. In the present retrospective study, cancer patients who received a totally implantable venous access port (TIVAP) in the upper arm using intracavitary electrocardiogram (ECG) guidance were compared with those where the traditional surface measurement method was used in terms of the rate of correct placement of the catheter tip, the rate of achieving the best position, the operation time and the complications. The results indicated that the correct placement rate and the best position rate of the catheter tip at the first attempt were higher in the ECG-guided group than in the traditional surface measurement method group (95.65 vs. 82.91% and 90.58 vs. 68.38%, respectively). The mean operation time was shorter in the ECG-guided group than in the surface measurement group (46.28 vs. 63.26 min). The incidence of complications in the ECG-guided group was 6.52%, while that in the surface measurement group was 10.26%. This indicated that the intracavitary ECG-guided tip positioning technique may improve the accuracy of tip catheter placement and shorten the operation time, thus reducing ionizing radiation caused by repeated positioning. Therefore, the intracavitary ECG-guided tip positioning technique is able to effectively place the tip of the TIVAD in the upper arm, holding great promise as a clinical application.