Eosinophils and neutrophils play major roles in pathogenesis of allergy.However the relation between peripheral blood cell counts of other major leukocyte groups, Hb%, ESR in allergic diseases is less clear.Therefore this study was conducted to find out if there is any variation in the haematological profile in subjects having allergic disease. Method: 50 cases of bronchial asthma, 50 cases of some allergic skin disorders and 50 cases of allergic rhinitis and 50 controls were chosen for this study. The study design was cross-sectional. Total Leucocyte Count, Absolute Eosinophil Count were done using Neubauer’s chamber, Differential Leucocyte Count by Leishman’s staining and Erythrocyte Sedimentation Rate using Westergren’s method. Haemoglobin estimation was done by cyanmethaemoglobin method. The statistical analysis was done using one way analysis of variance (ANOVA) followed by t test. Result: The results showed a significant increase (p<0.05) in the Total Leucocyte Count, Absolute Eosinophil Count, Erythrocyte Sedimentation Rate and the differential counts of neutrophil and eosinophil, and a significant decrease (p<0.05) in the lymphocyte count among the cases as compared to the controls. Conclusion: It is seen that in allergic condition besides an increase in the eosinophil count, other haematological parameters also change.