"Objectives: Calculations based on serum creatinine (SCr) are frequently used to estimate glomerular filtration rate (GFR). When Cr readings vary between laboratories, such creatinine (Cr)-based equations may provide erroneous estimations of GFR. The primary objective of this study was to determine the extent to which this variation exists in Cr assays across multiple laboratories in Ghana and to determine the influence of this variation in serum creatinine concentration results on the calculated estimated glomerular filtration rate (eGFR) and its impact on patients' classification of renal health. Method: This study involved six different individuals in six different laboratories. Serum Creatinine was measured in 36 serum samples using six analyzers and six creatinine techniques (5 enzymatic and one colorimetric (Jaffe)). The mean was calculated for each sample, and the interlaboratory creatinine variation was obtained. To normalize the results obtained from the creatinine measurements, it was necessary to determine urea and electrolytes (Na, K, Cl) concentration for all volunteers in the same laboratories, using the same serum samples. Cr readings varied significantly between laboratories. Results: There was substantial variability in Cr assays across the laboratories. The coefficient of variation between these laboratories in Ghana was 16% - 18%. Conclusions: Due to the high variability in SCr assays between laboratories, SCr measurements must be calibrated to a common standard. Failure to do so may significantly impact clinical interpretations when GFR is estimated using Cr-based calculations. We suggest that efforts should be made to standardize plasma creatinine measurement across all laboratories to minimize these problems."