ObjectivesTo address structural determinants and healthcare workers’ (HCWs) physical, mental, emotional and professional challenges of working during the COVID-19 pandemic.DesignExploratory qualitative study with semistructured interviews. Collected data were analysed using thematic analysis.SettingThis qualitative study was undertaken with HCWs who mainly worked in intensive care units in six non-profit hospitals in Vienna, Austria. Data were collected from June 2020 to January 2021.ParticipantsA total of 30 HCWs (13 medical doctors, 11 qualified nursing staff, 2 nurse assistants, 2 physiotherapists and 2 technical/cleaning staff) who were in direct and indirect contact with patients with COVID-19 were included.ResultsThree overall themes resulted as relevant: challenges due to lack of preparedness, structural conditions, and physical and mental health of HCWs. Lack of preparedness included delayed infection prevention and control (IPC) guidelines, shortages of personal protective equipment combined with staff shortages (especially of nursing staff) and overworked personnel. Physical and mental strains resulted from HCWs being overworked and working permanently on alert to face medical uncertainties and the critical conditions of patients. HCWs lacked recognition on multiple levels and dealt with stigma and avoidance behaviour of colleagues.ConclusionTo mitigate HCWs’ occupational health risks and staff turnover, we propose context-specific recommendations. The number of available essential workers in care of patients with COVID-19, especially nursing staff, should be carefully planned and increased to avert chronic work overload. Timely training and education in IPC for all HCWs is important. Providing supportive supervision is as essential as appropriate recognition by higher level management and the public.