Sarawak General Hospital, which is the only public access tertiary referral center in Sarawak State for all clinical specialties, was designated a hybrid hospital to treat both COVID-19 and non-COVID-19 patients. During the initial surge of patients admitted with COVID-19, there was also a corresponding increase in health-care workers (HCWs) detected with COVID-19 infection. The latter being isolated, and the large number of staff members that had come into contact with COVID-19 being quarantined from work, placed further strain on the health-care services. The staff mass screening strategy was a policy decision made by the hospital in response to infection among HCWs, and it aimed to reduce in-hospital transmission (particularly among asymptomatic staff), mitigate workforce depletion due to quarantining, and protect the health-care workforce. In this study, we assessed the detection rate of COVID-19 infection from staff mass testing over a five-week period, and described our experience of adopting this surveillance screening strategy alongside ongoing contact tracing and symptomatic screening strategies. Although it was thought that such periodic staff surveillance might be helpful in protecting the health-care workforce within a short period, the long-term implications, especially in settings with limited resources, is significant and therefore explored in this paper. Our findings might provide an evidence-based reference for the future planning of an optimal strategy with the least compromise in care for a larger proportion of non-COVID-19 patients amid efforts against COVID-19 in a large non-COVID-designated hospital with hybrid status.