Summary Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is incurable with conventional therapies. Limited retrospective data have shown durable remissions after haematopoietic cell transplantation (HCT) [allogeneic (allo) or autologous (auto)]. We conducted a multicentre retrospective study in BPDCN patients treated with allo-HCT and auto-HCT at 8 centres in the United States and Canada. Primary endpoint was overall survival (OS). The population consisted of 45 consecutive patients who received an allo-HCT (n = 37) or an auto-HCT (n = 8) regardless of age, pre-transplant therapies, or remission status at transplantation. Allo-HCT recipients were younger (50 (14–74) vs. 67 (45–72) years, P = 0·01) and had 1-year and 3-year OS of 68% [95% confidence interval (CI) = 49–81%] and 58% (95% CI = 38–75%), respectively. Allo-HCT in first complete remission (CR1) yielded superior 3-year OS (versus not in CR1) [74% (95% CI = 48–89%) vs. 0, P
