Imatinib is a new promising therapeutic option for chronic myeloid leukemia (CML) with efficacy even in the blast phase of the disease. However, most patients treated with imatinib in the blast phase develop progressive disease rapidly. Thus, treatment with imatinib has to be followed by other treatment strategies. The normally mild to moderate side effects of imatinib including skin rashes might therefore be aggravated. Here, we describe a patient with severe epidermal necrolysis after treatment with imatinib and consecutive allogeneic hematopoietic stem cell transplantation. Prolonged inhibition of platelet-derived growth factor by imatinib may be an explanation for this observed skin toxicity.