Urinary albumin measurement is very important laboratory examination, namely for diagnosis of renal complications in diabetes mellitus. The methods of measurement of urinary albumin are at present under intensive development and revision. Many recent communications describe that urinary albumin loses after passage through kidneys the part of its immunoreactivity. This should be the reason of obtaining the falsely lower results of urinary albumin obtained by immunochemical methods in comparison with HPLC. The decrease of immunochemical results is bigger in diabetic patients than in non diabetic subjects. Our brief communication deals with possible reasons of this phenomenon and also with its consequences for diagnosis. This problem can be resolved by introduction of new separation methodology instead of immunochemistry. Then will follow creating the certified reference materials and establishing the new reference values. We also introduce alternative approach to the explanation of urinary albumin problem, based on the non- -specificity of HPLC method.

        Key words: urinary albumin, immunochemical methods, HPLC, immunoreactivity, systematic differences.