Purpose: Chimeric antigen receptor T-cell (CAR-T) therapy is increasingly being used in the management of haematological malignancy (HM). The immune-modulating effects and cytopenias can blunt early signs of soft-tissue infection and delay recognition of necrotising soft-tissue infection (NSTI). We report a fatal case of NSTI after CAR-T, alongside a systematic scoping review summarising characteristics of NSTI in CAR-T recipients with HM. Methodology: Systematic scoping review (JBI; PRISMA-ScR) using MEDLINE, Embase, CENTRAL and Web of Science. Two reviewers independently screened with conflicts resolved by senior surgeon. Characteristics, progression of infection, immune status, microbiology, management (antimicrobial, surgical and ICU) and outcomes were collated. Case details were extracted from electronic medical records. Results: A 79-year-old man underwent CAR-T for transformed follicular lymphoma and developed forearm pain and erythema near a venous catheter. He was initially haemodynamically stable, but within 6 hours deteriorated to septic shock with rapidly progressive skin changes. Emergency exploration showed grey non-viable muscle deep to fascia without dishwater fluid or frank fascial necrosis. He arrested intra-operatively despite attempted shoulder disarticulation. Multiple specimens and two blood-culture sets grew heavy S. maltophilia, consistent with disseminated infection. Review status at submission: 2173 records imported; 151 duplicates removed (67 manual, 84 Covidence); 2021 screened; 1892 excluded; 129 full texts under assessment; synthesis pending. Conclusion: In CAR-T recipients, STIs may progress rapidly with attenuated early signs and laboratory markers, and atypical presentation. This case demonstrates a lethal NSTI due to an uncommon multidrug-resistant Gram-negative organism. The systematic scoping review will summarise outcomes across available evidence to define red flags and inform empirical management for this high-risk population.