Background: Extensive environmental contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in hospitals during pandemic coronavirus disease 2019 (COVID-19). We highlighted the practice of directly-observed environmental disinfection (DOED) in the community isolation facility (CIF) and community treatment facility (CTF) in Hong Kong. Methods: CIF (250 single-room bungalows in a holiday camp) was opened on July 24, 2020 to receive step-down patients from hospitals, while CTF (500-bed of open-cubicle inside a conventional hall) was activated on August 1, 2020 to admit newly diagnosed COVID-19 patients from the community. Healthcare workers (HCWs) and cleaning staff received infection control training to reinforce donning and doffing of personal protective equipment and understand the practice of DOED, where the cleaning staff observed patients’ and staff activities and then performed environmental disinfection immediately after their use. Supervisors also observed cleaning staff to ensure the quality of work. In CTF, air and environmental samples were collected on day 7, 14, 21, and 28 for SARS-CoV-2 by RT-PCR, while patients’ compliance of wearing mask was recorded. Results: Of 291 HCWs and 54 cleaning staff, who managed 243 and 674 patients in CIF and CTF, respectively, from July 24 to August 29, 2020, none of them acquired COVID-19. All 24 air samples and 520 environmental samples collected in the patient area of CTF were negative for SARS-CoV-2. Patients’ compliance of wearing mask was 100%. Conclusion: With appropriate infection control measures, zero environmental contamination and nosocomial acquisition of COVID-19 among HCWs and cleaning staff could be achieved.