Abstract Allogeneic stem cell transplant (allo-SCT) is considered a clinical option for patients with Hodgkin lymphoma (HL) who have experienced at least two chemosensitive relapses. The aim of this systematic review was to determine the benefits and harms of allo-SCT with an unrelated donor (UD) versus related donor (RD) allo-SCT for adult patients with HL. Alternative donor sources such as haploidentical donor cells (Haplo) and umbilical cord blood (UCB) were also included. The available evidence was limited. Ten studies were included in this assessment. Four studies provided sufficient data to compare UD with RD allo-SCT. None of these studies was a randomized controlled trial. Additionally, three non-comparative studies, such as registry analyses, which considered patients with UD transplants were included. The risk of bias in the studies was high. Results on overall and progression-free survival (PFS) showed no consistent tendency in favor of a donor type. Results on therapy-associated mortality and acute (grade II-IV) and chronic graft-versus-host disease were also inconsistent. The study comparing UCB with RD transplants and two non-comparative studies with UCB transplants showed similar results. One of the studies comparing additionally Haplo with RD transplants indicated a benefit in PFS for the Haplo transplant group. In summary, our findings do not indicate a substantial outcome disadvantage of UD and alternative donor sources versus RD allo-SCT for adult patients with advanced HL.