Nine patients with mycosis fungoides in different stages were treated with Bleomycin. Much better results were obtained with this new drug in the six patients with the infiltrative or beginning tumour stage than in the patients in the advanced tumour stage. Complete remission was not seen. In one case the results were objectivized by DNA cytophotometry. The role of Bleomycin in the treatment of mycosis fungoides is discussed. It is concluded that Bleomycin is not the medicament of choice for the treatment of mycosis fungoides.