In the context of the COVID-19 pandemic and overloaded hospitals, a central issue is the need to define reliable and consensual criteria for hospitalization or outpatient management in mild cases of COVID-19. Our aim was to define an easy-to-use clinical rule aiming to help emergency physicians in hospitalization or outpatient management decision-making for patients with suspected or confirmed SARS-CoV-2 infection (the HOME-CoV rule). The Delphi method was used to reach a consensus of a large panel of 51 experts: emergency physicians, geriatricians, infectious disease specialists, and ethical consultants. A preliminary list of eligible criteria was compiled based on a literature review. Four rounds of anonymized expert consultations were performed. The experts were asked to score each item as relevant, possibly relevant and non-relevant, as major or minor, and to choose the cut-off. They were also able make suggestions and remarks. Eight criteria constituting the HOME-CoV were selected: six correspond to the severity of clinical signs, one to the clinical course (clinically significant worsening within the last 24 h), and the last corresponds to the association of a severe comorbidity and an inadequate living context. Hospitalization is deemed necessary if a patient meets one or more of the criteria. In the end, 94.4% of the experts agreed with the defined rule. Thanks to the Delphi method, an absolute consensus was obtained of a large panel of experts on the HOME-CoV rule, a decision-making support mechanism for clinicians to target patients with suspected or confirmed COVID-19 requiring hospitalization. Trial registration: NCT04338841.