OBJECTIVES: The clinical outcome after allogeneic haematopoietic stem cell transplantation (aHCT) relies greatly on the efficient recovery of T cells. Several studies have investigated the short-term γδ T cell reconstitution and their role in clinical outcomes following haematopoietic stem cell transplantation. Nevertheless, their long-term characteristics and impact have remained largely unknown. METHODS: We analysed γδ T cells from 20 recipient/donor pairs at phenotypic, clonotypic and functional levels to assess their reconstitution ≥ 8 years (median 18 years) post-transplantation using high-parameter flow cytometry and next-generation sequencing of the TCR γ-chain. RESULTS: γδ T cells displayed comparable phenotypic characteristics between recipients and matching donors. The Vδ2 CONCLUSION: Overall, γδ T cells reconstitute with a normalised repertoire, high functional capacity and sustained CMV control ability. An increased proportion of activated Vδ1