[en] ¹⁶⁷Thulium was produced by spallation-reaction with high energy protons on tantalum targets. The tantalum targets were irradiated at the internal proton beam of the Dubna synchrocyclotron. After execution of the separation steps it is available very pure and carrierfree. The biokinetics and the distribution were studied in mice by means of specimen measuring, scanning and whole body autoradiography. Comparison with ⁶⁷Ga on one hand and rare earths radionuclides on the other hand were possible by way of simultaneous investigations. Specimens of organs, blood and secretions were investigated via gammaspectroscopy for their contents of radioactivity. ¹⁶⁷Tm was accumulated in all tumours up to 10 % per g tumour tissue but also in the liver, in the sceleton and in considerable amounts in inflammatory lesions. The high tumour/blood and tumour/muscle radioactivity ratios are promising attributes for future use in scintigraphy. Compared to ⁶⁷Ga ¹⁶⁷Tm allows to start imaging early after application and in addition shows little abdominal background. Among the rare earths radionuclides ¹⁶⁷Tm represents the most favourable one because of its radiation quality and its biokinetics. (author)