The incidence of deep venous thromboses (DVTs) associated with peripherally inserted central catheters (PICCs) in patients with hematological malignancies is not well described. We sought to determine the incidence, characteristics, and outcomes of PICC-related DVTs in this patient population. Retrospective, single center cohort analysis of patients with hematological malignancies with upper extremity PICCs and symptomatic upper extremity DVTs were identified by electronic medical record databases search. Between April 2001 and February 2006, 899 PICCs were placed in 498 patients, and ultrasound documented DVTs were observed in 39 (7.8%) a median of 26 days after PICC placement. Twenty-three (59%) had a new diagnosis of hematological malignancy at the time of PICC placement. DVT management included PICC removal (71%), thrombectomy/thrombolysis (13%), and 3-month anticoagulation. No pulmonary emboli or hemorrhages were observed. A change to centrally inserted tunneled internal jugular (IJ) catheters was instituted February 2006, and the incidence of DVTs was 0.4% among 843 tunneled IJ catheters placed in a subsequent cohort of 667 patients with hematological malignancies. Patients with hematological malignancies have a high incidence of PICC-associated DVTs. Internal jugular vein tunneled PICCs are associated with a very low incidence of DVTs in this patient population.