Objectives: Automated hematology analyzer generates flags for white blood cells abnormalities, indicating associated manual peripheral blood film examination. This study was aimed at evaluation and correlation of abnormal cell flagging with manual blood film reviews to improve performance in a hematology laboratory. In this study, an automated slide maker SC-120 was used to study the performance of fully automated haematology analyzer Mindray BC-6800. Methods: Total 500 routine samples were obtained over a period of seven consecutive days, and run through analyzer which displayed flags for white blood cells. Thereby, results from flags were evaluated and correlated with smear findings through careful statistical analysis of the observed parameters. Results: Flags for white blood cells and Nucleated Red Blood Cells (NRBC) were generated by BC-6800 for 211 samples out of total 500 run samples, from which 46.45% patients were diagnosed with haematological disorder and 53.55% with solid neoplasms. Sensitivity, specificity and Youden__ampersandsignrsquo;s Index observed against total 500 samples were 100%, 99.31% and 0.99 respectively. Efficiencies for blasts, abnormal lymphocytes and atypical lymphocytes were 95.64%, 95.20% and 97.60% respectively, whereas sensitivity for blasts was 75.81%. Further, sensitivity and specificity of NRBC were 86.76% and 100% respectively. Youden__ampersandsignrsquo;s index observed for various flags was close to 1, indicating near to satisfactory performance of analyzer. Conclusion: The present study confirms that performance of an automated analyzer aligns with standard manual methodology. However, to avoid false-negative results by analyzer, peripheral smears should be examined manually.