Donor lymphocyte infusion has been used in the management of relapsed disease hematological malignancies after allogeneic hematopoietic cell transplantation. It can eradicate minimal residual disease or be used to rescue a hematological relapse, being able to induce durable remissions in a subset of patients. With the increased in the use of haploidentical hematopoietic cell transplantation, there is renewed interest in the use of donor lymphocytes to either treat or prevent disease relapse post-transplant. Published retrospective and small prospective studies have shown encouraging results with therapeutic donor lymphocyte infusion in different haploidentical transplantation platforms. In this consensus paper, finalized on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarized the available evidence on the use of donor lymphocyte infusion from haploidentical donor and provide recommendations on its therapeutic, pre-emptive and prophylactic use in clinical practice.