As a response to the COVID-19 pandemic, the Royal Prince Alfred Hospital in New South Wales, Australia, launched the rpavirtual program, the first full-scale virtual hospital in Australia, to remotely monitor and follow-up stable COVID-19 patients. As part of the intervention, a pulse oximeter wearable device was delivered to patients to monitor their oxygen saturation levels, a critical indicator of COVID-19 patient deterioration. Understanding users' perceptions towards the device is fundamental to assessing its usability and acceptability and contributing to the effectiveness of the intervention, but no research to date has explored the user experience of the pulse oximeter for remote monitoring in this setting. To explore the utilization, performance, and acceptability of the pulse oximeter by clinicians and patients in rpavirtual during COVID-19. Semi-structured interviews and usability testing were conducted. Stable COVID-19 adult patients (≥18 years old) who used the pulse oximeter and were monitored by rpavirtual and rpavirtual clinicians monitoring these patients were interviewed. Clinicians could be nurses, doctors or staff part of the team who assisted patients with the use of the pulse oximeter. Usability testing was conducted with patients who had the pulse oximeter when they were contacted. Interviews were coded using the Theoretical Framework of Acceptability. Usability testing was conducted using a think-aloud protocol. Data was collected until saturation was reached. Twenty-one patients (average age: 51 years) and 15 clinicians (average age: 41 years) completed the interview. Eight patients (average age: 51 years) completed the usability testing. All participants liked the device and thought it was easy to use. They also had a good understanding of how to use the device and the device's purpose. Patient age and device-use related characteristics (e.g., the warmth of hands, hand steadiness) were identified by users as factors negatively impacting the accurate use of the pulse oximeter. Patients and clinicians had very positive perceptions of the pulse oximeter for COVID-19 remote monitoring, indicating high acceptability and usability of the device. However, factors that may impact the accuracy of the device should be considered when delivering interventions using the pulse oximeter for remote monitoring. Targeted instructions about the use of the device may be necessary for specific populations (e.g. elderly, patients unfamiliar with technology). Further research should focus on the integration of the pulse oximeter data into electronic medical records for real-time and secure patient monitoring.