In patients presenting with atraumatic joint pain and swelling, diagnosis is typically made by synovial fluid analysis. Management of an acute suspected hip joint arthritis can present a challenge to the emergency physician (EP). Hip joint effusions are somewhat more difficult to identify and aspirate than effusions in other joints that are commonly managed by EPs. Identification and aspiration of a hip joint effusion under ultrasound guidance is a well-established procedure in the fields of orthopedic surgery and interventional radiology. Here, we report 4 cases of ultrasound-guided hip arthrocentesis at the bedside by EPs; relevant technical details of the procedure are reviewed. These cases demonstrate the feasibility of ultrasound-guided hip arthrocentesis in the emergency department (ED) by EPs. With increasing availability of bedside ultrasound in the ED, suspected hip joint arthritis or infection may be evaluated and managed by the trained EP in a fashion similar to other joint arthritides.