OBJECTIVES: A dearth of qualitative studies constrains in-depth understanding of health service providers' perspectives and experiences regarding the impact of COVID-19 on their mental health. This study explored the mental health impact and needs of of public sector healthcare workers during COVID-19 who working in secondary-level and tertiary-level healthcare settings of Pakistan. DESIGN: An exploratory qualitative study. SETTING: Twenty-five secondary-level and eight tertiary-level public hospitals of Sindh and Punjab provinces of Pakistan. PARTICIPANTS: In-depth interviews were conducted with 16 health service providers and 40 administrative personnel. Study data were analysed on NVivo V.11 using the conventional content analysis technique. RESULTS: The study identified three overarching themes: (1) mental health impact of COVID-19 on health service providers that included the fear of acquiring the infection and transmitting it to their family members, fear of social isolation and stigma, anxiety related to the uncertainty of COVID-19, nervousness due to media exaggeration and stress associated with excessive workload; (2) mental health needs of health service providers involved in the COVID-19 crisis and available support from the healthcare system, including the expression of the need for counselling services and safe working conditions, the need for paid rest periods, and the need for appreciation and motivation to work in the pandemic; and (3) suggestions to address mental health needs of healthcare workers, including provision of specialised mental healthcare/services, formal training of health managers on managing mental health needs of health facility staff, and assessment and addressing of these needs of the health workforce. CONCLUSION: The study emphasises the need to strengthen health system preparedness for recognising and addressing the needs of healthcare professionals. At the system level, there is a need for a specialised unit to provide mental health services and better communication strategies. At the staff level, continuous motivation and appreciation should be given to healthcare professionals either through monetary incentives or formal acknowledgement of their performance.