The analytical errors may be random or systematic which is denoted basically by inaccuracy and imprecision. These parameters are represented by coefficient of variation (CV) and Bias. Six sigma (σ) is a quality management tool to assay quality which combines bias, precision and total allowable error (TEa). Sigma level < 3 indicates poor performance whereas >3 indicates good performance.This retrospective study was conducted at central laboratory of IQ City Medical College and Narayana Multispecialty Hospital. The laboratory uses the auto–analyzer Siemens Dimension and hexokinase method for glucose.The two levels of QC (L1 and L2) are run daily. The internal QC data of the analyte was extracted from the record for month June 2016. The % CV, % Bias was calculated from peer groupQC reports. The σ value was calculated usingTEa (from CLIA), Bias and CV.The laboratory mean and standard deviation for quality control material(L1 level) was 87.7 ± 2.08 and the same for L2 was 272.9 ± 2.4. The CV % for L1 and L2 was found 2.37 and 0.87 % respectively. The designated mean (DM) was 89.53 and 284.4 for L1 and L2 respectively. The number of laboratory (peer group) participated for L1 and L2 were 98 and 97 respectively utilizing same lot no. QC material (Biorad), same instrument and same method. The Bias for L1 and L2 was found –2.04 and –4.04 respectively. The six sigma was found 3.35 and 6.85 respectively for L1 and L2.The sigma metrices along with other quality indicators like %CV, Bias may have better impact on quality check of analytical performance in clinical laboratory.