Primary plasma cell leukaemia (PCL) is a rare, aggressive neoplasm of plasma cell dyscrasia. Conventional chemotherapy is usually ineffective, with an overall survival of only 8 months. Here, we describe a 42-year-old man with primary PCL, who was successfully treated with haploidentical (2-HLA loci mismatched) haematopoietic stem-cell transplantation (HSCT). To overcome the human leukocyte antigen (HLA) disparity, in vivo T-cell purging by the pre-transplant administration of antithymocyte globulin followed by a conventional prophylactic treatment against graft-versus-host disease (GVHD) resulted in an avoidance of severe GVHD as well as infectious complications. The patient has maintained complete remission for 13 months after haploidentical HSCT, indicating that a graft-versus-PCL effect might be preserved. Haploidentical HSCT can be a potentially curative treatment for patients with primary PCL who do not have an HLA-identical donor.