Automated counts are being widely accepted in diagnostic field due to various advantages. Despite the sophistication of present day instruments there is still need to depend on manual techniques for primary calibration especially in case of platelet count. Automated analyzer had pitfalls due to mimickers of platelet like particles which validated the manual count in peripheral smear regarding platelet count by leishman’s stain. A cross sectional study was conducted in a tertiary care hospital for 3 months. It includes 1200 venous samples with EDTA as the anticoagulant in vacutainers. Among the routine 100 to 120 samples/day, with platelets < 1,00,000 lakhs /cumm of 500 samples were subjected for study. Samples were processed by Symex 5000 autoanalyzer and compared with manual platelet count by leishman’s stain. About 500 samples with platelets < 100,000 lakh/cu.mm were taken for study. In 384/500(76.8 %)haematology analyzed correlated with peripheral smear review. About 116(23%) were not correlating with peripheral smear findings because it revealed RBC’s and large platelets in peripheral smear. Our study concludes there was significant correlation between automated and manual counts. But this was not applicable for very high or low platelet counts.As platelet count estimation is very important element of the diagnostic and treatment disorder.Peripheral smear examination along with automated analyzer valid in case of high or low value platelet counts.