Background: A large number of patients with sickle cell anaemia are in steady state as a result of high level of fetal haemoglobin (HbfF). However, few of those with low HbfF levels usually have bone pain crisis intermittently. Considering the delicate nature of these patients, it is therefore imperative to carry out this study. Aim of the Study: The aim of this study is to determine the haematological parameters in adult with sickle cell anaemia in steady state visiting a tertiary hospital (Ahmadu Bello University Teaching Hospital) Zaria, Kaduna, Nigeria, with a view to providing a predictive data of SCA patients haematological parameters, as well as contribute to effective management of the disease. Materials and Method: This cross-sectional study was conducted in a tertiary hospital. Sixty (60) participants consisting of thirty (30) individuals with HbSS in steady state and thirty (30) apparently healthy HbAA controls were enrolled into the study. Result: The study revealed significantly higher mean white blood cell (WBC) and platelets count in the subjects with p value of < 0.005 but significantly lower mean haemoglobin and haematocrit (P< 0.005). Conclusion: Considering the role of leukocytosis and thrombocytosis in vaso-occlusion, it is therefore advisable to monitor patients with sickle cell anaemia closely and get them prevented from triggering factors to crisis as much as possible.