OBJECTIVES: The present study was designed to compare the performance of a new oxygen delivery device, the OxyArm (OA) (Southmedic Inc, Canada), with a standard nasal cannula (NC) (Salter-Style 1600, Salter Labs, USA) for both oxygen delivery and patient preference in patients on long-term oxygen therapy (LTOT). DESIGN AND SETTING: Randomized crossover study conducted in an outpatient setting. PATIENTS AND METHODS: Twenty-five clinically stable LTOT patients were randomly assigned to an oxygen device (NC or OA) sequence. The baseline saturation level was determined, and patients were then treated at oxygen flow rates of 2 L/min, 3 L/min, 4 L/min, 5 L/min, 6 L/min and 7 L/min for 10 min each while at rest. Patients were then crossed over to the second device and the procedure was repeated. Oximetry values were then obtained following a 5 min walk test using the same device sequence. Lastly, the patients were sent home for a four-week home OA trial, after which, they filled out a questionnaire. RESULTS: This sample of patients was primarily elderly ex-smokers with severe chronic obstructive pulmonary disease on oxygen therapy for the majority of the day. The primary findings were that the OA and NC were equally effective in delivering oxygen to patients and maintaining their oxygen saturation at both rest (P=0.82) and during a 5 min walk test (P=0.83). A patient's personal experience and comfort were identified as the most important factors in deciding on an oxygen device. Most patients felt that the OA was most suited for oxygen therapy while at rest. CONCLUSIONS: The OA proved to be similar to the NC in delivering oxygen and maintaining saturation in patients on LTOT. The OA is one of the few alternatives to using NCs for these patients and, with its current design, appears to be most suited for resting conditions.