Background Necrotising soft tissue infection, or necrotising fasciitis, is a rapidly progressing disease requiring immediate diagnosis and treatment consisting of antimicrobial therapy, hyperbaric oxygen, debridement surgery and treatment in the intensive care unit. The harrowing illness trajectory affects the family caregivers potentially producing long-term psychological issues.Objectives We aimed to explore the experiences and coping strategies of family caregivers during the first six months after patient diagnosis of necrotising soft tissue infection. Methods Our study had a prospective, explorative, qualitative design using semi-structured interviews and thematic analysis to understand necrotising soft tissue infection as an intrinsic and instrumental case. Family caregivers (n = 25) were recruited at three university hospitals in Denmark and Sweden. Findings We identified three chronological themes describing issues of importance to the family caregivers. In the intensive care unit: Coping with illness and intensive care; In the ward: Coping with injury and post-intensive care and At home: Coping with recovery and new home life. Conclusion Challenges facing family caregivers of necrotising soft tissue infections survivors are still under-recognised. Healthcare professionals need to ensure that families and stakeholders throughout the patient trajectory have access to and co-create timely information and care plans to bridge the knowledge gap across care environments and to relieve family responsibility.