INTRODUCTION: Compression ultrasonography (CUS) is a validated technique for the diagnosis of deep venous thrombosis (DVT), but has never been studied with pocket-sized ultrasound device (PUD). The main objective of this study was to assess the diagnostic performance of CUS made by emergency physicians (EPs) using a PUD. MATERIALS: This was a prospective, diagnostic test assessment, single-center study. Patients underwent VCU performed by a trained EP with PUD (CUS-PUD) for searching proximal DVT (PDVT) and were then seen by an expert vascular physician who blindly performed a duplex venous ultrasound, which was the criterion standard. CUS-PUD's diagnostic performance was evaluated by sensitivity (Se), specificity (Sp), and positive and negative predictive values (PPV and NPV). RESULTS: The sample included 57 patients of whom 56 were analyzed. Eleven (20%) PDVT were diagnosed with CUS-PUD: 7 (64%) femoral and 4 (36%) popliteal. The CUS-PUD's Se was 100% [72%; 100%], Sp 100% [92%; 100%]. The PPV was 100% [74%; 100%], and the NPV was 100% [90%; 100%]. CONCLUSION: CUS-PUD performed with a pocket-sized ultrasound appears to be feasible in emergency practice for the diagnosis of proximal DVT. A study with a larger sample size will have to describe the accuracy.