The availability of a low-molecular-weight heparin, enoxaparin, to treat deep-vein thrombosis (DVT) offers the option for outpatient therapy for certain DVT patients. We monitored the utilization and outcomes of enoxaparin treatment for DVT in our tertiary-care hospital. A retrospective chart survey was performed for all DVT patients treated at our facility between October 1998 and September 1999. We tracked treatment received (unfractionated heparin or enoxaparin), clinical outcomes (recurrent thromboembolism or bleeding), and whether the patient would have met practice guideline criteria for outpatient enoxaparin therapy. A total of 266 patients were either admitted to the hospital for DVT or experienced DVT during their hospitalization. Of 266 DVT patients, 73 (27%) received enoxaparin. Sixty-four (88%) patients receiving enoxaparin met practice guideline criteria. Nine patients (12%) who did not meet criteria also received the drug. Major bleeding occurred in 3 patients (4%) receiving enoxaparin; one patient had a life-threatening hemorrhage. Two of the three patients with major bleeding had contraindications to enoxaparin use. Only 45% of our DVT patients were appropriate candidates for outpatient enoxaparin therapy. We conclude that in tertiary-care hospitals with acutely ill patients, most DVT patients will not be candidates for outpatient therapy with enoxaparin. Limitations to enoxaparin use are not widely appreciated.