[en] A systematic study was undertaken in order to find out which of the most relevant elements can be determined in water under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples as well as natural water of different kind were used, brought to dryness by freeze-drying and irradiated in quartz at a neutron flux of 10¹⁴n cm^-2s^-1 for 1 day. The trace element content in quartz ampoules of different origin was determined separately. The results of the critical evaluation of the data obtained and the experiences gathered in the course of trace element determination in standardized as well as natural water samples by non-destructive neutron activation analysis are summarized. The non-destructive determination of the following elements in natural water is without problems: Au, Br, Ca, Co, Cr, Eu, K, La, Na, Sc, U, Zn. There are no serious problems but interferences have to be taken into account in the case of the following elements: As, Fe, Mo, Sb, Se. Determination is problematic for Hg and not possible under these conditions for Cd, Cu, Ni. (T.G.)