Haematological alterations caused by coccidiosis in experimentally infected broiler chickens by Eimeria spp. The experimental animals (n=100) were randomly allocated into four equal groups, group one (G-I), group two (G-II), group three (G-III) and group four (G-IV) with 25 chickens in each group. The G-I, G-II, and G-III were treatments groups challenged by different Eimeria sporulated oocysts, while G-IV served as the control group. In this study, the infective dose of E. tenella (G-I), E. acervulina (G-II) and mixed Eimeria spp (G-III) was 2×104 sporulated Eimeria oocyst inoculated orally at three weeks of age in broiler chicken and subsequent alterations in different haematological constituents were evaluated at interval of 5, 7 and 9 day of post inoculation. Anaemia caused by Eimeria species was characterized by a decreased number of red blood cells and packed cell volume. Statistically highly significant decrease in the total erythrocyte count in all infected groups was recorded compared to control group. The mean value of total erythrocyte count of group one and group two recorded a highly significant decreased on 7 day of post infection. A highly significant increase in total leukocyte count in group one and group two Eimeria infected chickens. The statistical analysis of eosinophil and heterophils and lymphocyte showed highly significant increase in group one and group two in comparison to control group. The mean percentage of monocyte in group one, group two and group three revealed a highly significant increase on seven day of post infection.