Poor prognosis malignant lymphoma is often treated with autologous bone marrow transplantation. Relapse after transplantation is usually associated with disease progression and resistance to further therapy. We present a case in which a 50-year-old patient relapsed with multiple pulmonary metastases shortly after peripheral blood stem cell transplantation. Remarkably, this relapse remitted spontaneously. This may provide valuable insights into tumour cell biology and mechanisms by which stem cell mobilisation may alter this.