Plasmacytoid blast dendritic cell neoplasm is a rare subtype of acute leukaemia that represents less than 1% of haematologic neoplasms. It is characterised by skin involvement and leukaemic dissemination in the rest of the body. The immunophenotype is represented by the expression of CD4, CD56 and CD123. Due to its low incidence, there is no standardised treatment. For most authors, acute lymphoblastic leukaemia) regimens with or without consolidation with allogeneic transplantation seem to be the most appropriate. We present the case of a 31-year-old male with a history of von Willebrand’s disease, who was diagnosed with plasmacytoid blast dendritic cell neoplasm with central nervous system involvement. After receiving first-line immunopolychemotherapy with rituximab, the patient achieved complete haematologic remission with the high-dose ara-C regimen. Subsequently, he consolidated with allogeneic haploidentical transplantation.