Introduction Necrotizing soft tissue infections (NSTIs) are rare, rapidly progressing infections of the skin, fascia, and muscle causing necrosis, frequently requiring intensive care unit (ICU) admission. Treatment includes surgical debridement, organ support, antibiotics, and hyperbaric oxygen therapy (HBO). NSTIs require aggressive debridement, leaving survivors with wounds and functional deficits. Quality of life (QoL) is decreased in NSTI survivors, including physical and mental health. Our goal was to analyze the long-term outcomes of patients admitted to the ICU for NSTIs. We evaluated sequelae and QoL and aimed to correlate these with patient- and treatment-related factors. Methods All NSTI patients admitted to our ICU and treated with HBO between 2007 and 2021 were included. A review of medical records was followed by a phone interview. Demographic-, admission-, infection-, and treatment-related data were collected. Long-term outcomes analyzed included ICU/hospital mortality, one-year mortality, physical sequelae, functional capacity, and characterization of health-related QoL in 2022. Results Seventy-four patients were identified, 29 of which died and five were lost to follow-up. Patients were predominantly male, with a median age of 62 years. The median length of stay in ICU and hospital was 10 and 50 days, respectively. Fifty-nine (94%) patients were independent at admission (Clinical Frailty Scale (CFS) ≤4). NSTIs mainly concern the perineum or lower limbs. Most infections were polymicrobial and caused multiorgan dysfunction. The 30-day mortality was 22%, with a one-year mortality of 26%. Prevalent sequelae included hernias, scarring, and the need for intestinal ostomies. Most patients were independent on follow-up (CFS ≤ 4), denying limitations in mobility (23 patients, 61%), self-care (31 patients, 82%), or daily activities (26 patients, 68%). Chronic pain was identified in 16 patients (42%) and 13 patients (34%) reported anxiety or depression. The median value of self-perceived global health status was 72.5%. We found an association between mortality and illness severity. The small sample size regarding patient and treatment characteristics precluded further significant statistical analysis in our study. Conclusion NSTIs are life-threatening infections with lifelong consequences. Despite frequent physical sequelae, long-term QoL in NSTI survivors may be satisfactory, and long-term functional capacity may remain reasonable after acute disease resolution.