A study was conducted at the Department of Animal Science and Production, Sokoine University of Agriculture. The aim was to study the effect of different management systems on haematological parameters in layer chickens. Three management systems which are battery cage, deep litter and semi- intensive were involved. Ninety layer chickens, Rhode Island Red, eight weeks old were used. Thirty chickens were placed in each of the three systems. Seven chickens from each management system were selected randomly for blood collection. Blood was collected in every two weeks for two months. Blood was used to analyse for hematological parameters. It was observed that, RBC (x 106/ μl), PCV (%), Hb (g %) increased as the age of chicken was increasing. ESR (mm), MCH (pg) and MCHC (%) decreased as age of chickens was increasing. All mean values for the RBC (x 106/ μl), and WBC (x104/ μl) count, PCV (%), Hb (g %), ESR (mm), MCH (pg) and MCHC (%) did not differ (P>0.05) significantly among the management systems. No significant effect of management system on hematological parameters was observed. The differences in the values of hematological parameters among the management systems observed to be probably due to changes brought about by age and individual bird variation. Concluding that RBC (x 106/ μl), PCV (%), and Hb (g %), had a direct relationship with age while ESR (mm), MCH (pg) and MCHC (%) were indirectly related. Since no significant effect was observed in the haematological parameters for the chickens under the three management systems, then other factors such as risk of diseases, sanitation, costs should be considered in deciding which system to be used. Deep litter system is advocated to be used by the poultry keeper because of its less cost and less risk of predators, and climatic extreme changes.