Since 2006 clinical guidelines have recommended that the estimated glomerular filtration rate should be calculated from serum creatinine for the early detection of chronic kidney disease. These brought into the limelight the limitations of the Jaffe method and for comparability of test results the different routine creatinine methods need to be harmonized. The disadvantage of the kinetic Jaffe creatinine determination is its low specificity. This was improved by the enzymatic, compensated-Jaffe and high resolution liquid chromatographic assays introduced in the last decade. Creatinine values determined by the new methods are more accurate, but give lower creatinine values, therefore the glomerular filtration rate would be overestimated, if the new creatinine results were applied in the previous formulae (4-variables Modification of Diet in Renal Disease-186, Cockcroft-Gault, Quadratic). Because of the new creatinine methods estimation of the glomerular filtration rate and classification in chronic kidney disease staging became uncertain. Therefore the 4-variables Modification of Diet in Renal Disease-186 formula has been adjusted in 2006 and for the new creatinine methods (traceable to the isotope-dilution mass spectrometry) only the new Modification of Diet in Renal Disease-175 formula is advised. Authors compare the diagnostic value and limitations of the creatinine methods.