Introduction: Tobacco smoking is the most important preventable cause of human morbidity and mortality. Cigarette smoke is a heterogenous aerosol produced by incomplete combustion of tobacco leaf. Aim: To compare and correlate the haematological parameters– RBC count, WBC count, Haemoglobin level, Haematocrit (PCV) values between chronic smokers and non smokers. Materials & methods: 70 male smokers and 50 male non–smokers in the age group of 31 to 50 years residing at Coimbatore were selected. Fresh blood samples were collected for the estimation of RBC count, Total WBC count, Haemoglobin level and Haematocrit. Measurement of Blood Parameters was done by Automatic cell analyser. Results: This study showed rise in RBC count, WBC count, Haemoglobin and PCV values (P value < 0.05) in chronic smokers compared to non–smokers in all age groups. Conclusion:  Haematological changes indicate that chronic smokers have high liability to cardiovascular risk due to haemoconcentration than non–smokers in future.