The increasing number of COVID-19 patients during the pandemic posed a great challenge for health care services. Nurses play a vital role in in providing care to these patients and managing other health care services, which created a significant challenge in regard to work force management and competency varied with a hospital’s resources. This qualitative research aimed to discover the lessons we can learn from the COVID-19 crisis experience which can lead to policy suggestions regarding workforce management and nurse competency at the secondary and tertiary care levels in the 10th Public Health Region of Thailand. Document analysis, in-depth interviews, and focus group discussions were used to collect data from October 2021 to April 2022. The 293 key informants included the Ministry of Public Health (MoPH) inspector for the 10th Public Health Region, representatives of the Thailand Nursing and Midwifery Council and the Nursing Division of the Ministry of Public Health, the Provincial Chief Medical Officer, a group from the Emergency Operations Center (EOC) Committee, hospital directors, heads of nursing departments, physicians, infection control (IC) nurses, and nurses engaged in COVID-19 patient care. The data were analyzed using content analysis. The study revealed two major findings as follow: First, workforce management in responses to the Covid-19 crisis in both the secondary and tertiary care setting included several similar strategies, namely: 1) implementation of pooled staffing using personnel from different units including nurses who volunteered when asked or were given direct ordereds, 2) using mixed-skill nursing staffing, and 3) assigning the head nurses of the units with lower workloads as supervisors in the COVID-19 cohort wards. However, some different strategies were implemented at the secondary care setting, including modifying working hours from 8-hour shifts to 12-hour shifts Last, having different nursing competency development models for COVID-19 care, which varied from setting to setting. The majority of competency development was on-the-job training, followed by pair-mentoring and self-directed learning strategies where staff searched the internet for available COVID-19 related resources to improve their knowledge about how to provide care for their patients. The IC nurses played a major role in increasing the hospital staff’s infection control competency, as well as updating and distributing the COVID-19 practice guidelines. Moreover, in the tertiary care settings, nurse competency development was focused on the essential skills required to care for critically ill and complicated patients and the technical skills related to using advanced technology medical equipment, negative pressure rooms, and other equipment related to COVID-19 patient care. The most common education and training conducted in the hospitals were related to the donning (putting on) and doffing (removing) of personal protection equipment (PPE) or powered air purifying respirators (PAPR), intubation of COVID-19 patients, Auto CPR, prone positioning of COVID-19 patients experiencing Adult Respiratory Distress Syndrome (ARDS), and mechanical ventilator care. The key to the success of the response to the crisis was the collaboration from all of the partners and stakeholders. The policy suggestions focus on designing and planning a comprehensive nursing workforce management and competency policy to handle crisis situations, developing the nursing workforce system and mechanisms in order to retain nurses in the system, implementing education and training programs to promote the continuous maintenance and improvement of nurses’ competencies, and creating a working environment which allows nurses to maintain their roles in providing direct patient care.