The Fleming Fund has supported antimicrobial resistance (AMR) surveillance capacity building in Zambia since 2018. In the human health sector, this support contributed to substantial improvements in laboratory infrastructure, equipment, workforce development, quality assurance, governance, and the routine use of data. These investments were associated with measurable gains in diagnostic capacity, sample throughput, laboratory performance, and antimicrobial stewardship (AMS) practices. The example of Livingstone Teaching Hospital (LTH), which has benefitted from the programme, illustrates how targeted investments can mature into functional surveillance systems that support clinical decision-making, influence prescribing behaviour, and inform policy. Our analysis shows that surveillance capacity can be established relatively rapidly when investments are well-sequenced and aligned with national priorities. However, sustaining and fully realising these gains is significantly more challenging. Recurrent costs, particularly consumables and equipment maintenance, remain heavily donor-dependent, while procurement failures, staff turnover, uneven engagement by clinicians, and reliance on individual champions reduce system resilience and efficiency. Cost and output analysis across sentinel sites also demonstrated economies of scale, with higherthroughput and more mature laboratories achieving lower costs per sample. Once laboratories move beyond the set-up phase, the principal sustainability challenge is no longer capital investment, but reliable financing for recurrent inputs, particularly consumables, equipment maintenance, and staff time. Without stronger domestic financing and more reliable procurement systems, recent gains risk erosion after donor support ends. At the same time, the Fleming Fund has created durable assets that provide a strong platform for future AMR-related interventions, including functional laboratories, skilled personnel, governance structures, and routine data flows. The central conclusion of this review is that sustainability is not only a financing issue, but a systems-alignment challenge. The long-term value of AMR surveillance depends on whether countries can embed diagnostic services, procurement, stewardship, and data use into routine, trusted, and financed health-system functions.