This case of upper extremity deep vein thrombosis is selected for case report as it is a rare form of deep vein thrombosis without a very well established treatment modality and prognosis. The objective of this study was to report the outcome of a 25 years old male patient with idiopathic upper extremity deep vein thrombosis treated conservatively with low molecular weight heparin (LMWH) and oral warfarin. The data sources used were patient interview, laboratory and radiology investigation results and patient charts. The patient had no apparent recurrence or complication for 3 years except the presence of occasional dull pain over the affected left upper extremity.