摘要:Background: Volunteers' presence, as a critical issue in hospital response to disasters and emergencies, helps to readiness and quick response to the phenomena, preventing deaths caused by such incidences. This study aimed to determine the main factors affecting popular volunteers' presence in hospital response to disasters and emergencies in Iran. Methods: This qualitative study, conducted on 31 semi-structured interviews during the years 2019 and 2020, concerning emergency specialist working in various health organization nationwide between June 2019 and April 2020. The non-structured and semi-structured interviews were adopted to gather concept code and analyzed using Graneheim recommendation method. Results: Four main categories, identified as effective factors on volunteers' presence in hospital response to disasters and emergencies, including nine subcategories: (1) organizing and managing volunteers (with two sub-categories: (a) calling and registering volunteers, and (b) identifying volunteers' ability); (2) organizational structure (with two sub-categories: (a) operational planning and (b) coordination and communication); (3) training (with two sub-categories: (a) training in disasters and (b) volunteer training); and (4) volunteer challenges (with three sub-categories: (a) volunteer interaction with organizations, (b) volunteer logistics, and (c)volunteering culture). Conclusion: Exploring effective factors as regards volunteers' presence in hospital response phase in disasters to adopt a policy based on the experiences of managers and heads of health can help planners to provide effective design and implementation. It can scientifically contribute to disaster risk management and hospital emergency response in Iran.