As a result of APA labelling with99mTc reduced by SnCl2at pH 1.9 about 90% of99mTc-APA complex was obtained. Experiments in vivo were carried out on 10 Swiss mice who had Ehrlich tumor inplanted. After 8 days the99mTc-APA complex was administered i. p. – The ADF ratio tumor blood was 2,5. Renoscintigraphy showed that the decline of renal activity, in the stage when excretion prevailed (phase III), was slow and of cumulative nature. Simple synthesis, labelling and low toxity of APA are the factors that advocate further experiments in searching its utility in diagnostics.