Six patients with advanced disseminated malignant lymphomas of the skin were treated with cytostatics using the method of partial synchronisation of the tumor cell growth phases. Though five patients had already shown a resistance against the usual chemo- and/or radiotherapy, all patients responded to this therapeutical principle. Full remission was achieved in four patients. We proved that vincristine effectively synchronizes the growth of proliferating human tumor cells in vivo. Treatment was applied in two steps. First a partial synchronisation of tumor cell growth was induced by vincristine as a pharmacologic means. Then the cytostatics were applied in killing doses at the calculated time. For this purpose we determined the average length of each generation of cells and developed individual therapy schemes. To get the best results with this method usually several therapy cycles were used. In case of a relapse the therapy scheme was adjusted to the altered cellular kinetics. This principal of partial synchronisation is suitable for treating malignant lymphomas with high efficiency, especially those with rapid proliferation even in advanced states.