This multicenter, prospective, open label, observational study evaluated practice patterns of physicians using tinzaparin, a low-molecular-weight heparin (LMWH), and warfarin for the treatment of deep venous thrombosis (DVT) with or without pulmonary embolism (PE). Short-term recurrence of venous thromboembolism (VTE) and safety were also evaluated. Patients with an objective diagnosis of DVT, with or without PE, were invited by their physician to participate in this study. Treatment was given according to the approved U.S. package inserts for tinzaparin (175 IU/kg SQ QD) and warfarin and the clinical judgment of the prescribing physician. Baseline patient history including demographic information and the results of tests to confirm the diagnosis of DVT, with or without PE, were collected. Follow-up information included the treatment setting in which each dose of tinzaparin was administered, medical training of the person administering tinzaparin doses, timing of initiation of warfarin with respect to that of tinzaparin, length of overlap of tinzaparin and warfarin therapy, and adverse experiences. A total of 334 patients were enrolled at 65 sites. Patients across a wide age (range 18-93 years old) and body weight (range 40-261 kg) were included. Overall, 27.3% of patients had cancer, and 50% of the overall study population reported more than one VTE risk factor. Mean duration of tinzaparin treatment was 7.61 days. Therapy at home was more common in suburban and rural settings than in urban settings. High proportions of patient, even among the small group with concurrent PE, were treated at home with self-injection. Severity of disease was the primary reason for hospitalization. Home treatment of DVT, with or without PE, with self administration of tinzaparin at 175 IU SQ once-daily was safe and resulted in an acceptably low rate of recurrent venous thromboembolism and adverse events. Home therapy in the usual practice setting should achieve substantial overall cost savings in the treatment of DVT.