BACKGROUND Sickle cell disease is a genetic disorder of haemoglobin with a world-wide distribution. Nigeria, the most populous African country has the highest cohort of sickle cell anaemia patients. Hence the need for more research studies on sickle cell disease in this part of the world. The clinical manifestation of sickle cell disease vary enormously ranging from asymptomatic to patients disabled by recurrent pain and chronic complications, the most devastating probably being occurrence of stroke in a patient with sickle cell disease. Sickle cell disease is considered a prethrombotic state; certain characteristics of sickle cell such as abnormal adhesivity and absence of membrane phospholipid asymmetry are involved in the thrombotic process. Most of the morbidity of sickle cell disease is related to the appearance of occlusion of the microvasculature resulting in widespread ischaemia and irreversible organ damage. Protein C is a Vitamin K dependent serine protease and naturally occuring anticoagulant that plays a role in the regulation of haemostasis by inactivating Factors Va and VIIIa in the coagulation cascades. Activated Protein C is a down regulator of blood coagulation resulting in protection against thrombosis. It also has anti-inflammatory effects through its inhibition of cytokine generation and also exerts profibrinolytic properties that facilitate clot lysis. OBJECTIVE To evaluate Protein C in Nigerian patients with sickle cell anaemia in steady state so as to assess their prothrombotic tendency compared with normal individuals. Sub-objectives Evaluation of Prothrombin time (PT), Activated partial thromboplastin time (APTT) and liver function tests (LFT) in sickle cell anaemia patients in steady state. METHOD The study was carried out at the University College Hospital Ibadan. The study population comprised of forty sickle cell anaemia patients who are in steady state, asymptomatic for at least two weeks and forty healthy normal HbA control subjects, age and sex matched who satisfy the inclusion criteria as contained in the methodology. Protein C was assayed with Amax Destiny plus Coagulometer using clot based method.