Abstract: The current research aims to study the incidence, diagnosis, and treatment of deep vein thrombosis ( DVT ) in breast cancer patients with peripherally inserted central catheters ( PICCs ) during chemotherapy. Methods: Data of the incidence, diagnosis, and treatment for the PICC-related DVT in 187 breast cancer patients who underwent chemotherapy from August 2009 to July 2011 were retrospectively analyzed. Results: A total of 188 PICCs were inserted in the patients from August 2009 until July 2011 and were followed up for a total of 14,399 catheter-days ( median, 76.6 d; range, 1-170 d ). Four ( 2.1% ) of the 188 PICCs were removed as a result of PICC-related DVT in 14 to 112 catheter-days after the catheter placement, with an incidence of 0.28 per 1,000 catheter-days. Conclusion: Application of PICC in breast cancer patients during chemotherapy is a safe and effective method. However, some patients may develop catheter-related DVT. To achieve a markedly satisfactory therapeutic effect, careful attention should be paid on the signs and symptoms of the patients.