We present a 42-year-old man with acute lymphoblastic leukemia and hypodiploidy at diagnosis. Chromosome count was 37, with a mixture of numerical and structural abnormalities. The patient died 9 months post diagnosis, during which time three further cytogenetic tests were performed. The core abnormalities seen upon diagnosis were present at 7 and 9 months after diagnosis, with a duplication of the abnormal hypodiploid karyotype on the last specimen. While considerable imbalances were present as a result of whole chromosome aneuploidy, no region was obviously nullisomic.