Most patients with sickle cell anaemia (SCA) show evidence of cardiac dysfunction. This study aimed at clinically and electrocardiographically assessing the exercise capacity of steady state SCA patients using self-paced walking exercise. Forty one (17 males and 24 females) steady state SCA patients between the ages of 15 and 37 years were prospectively studied with 41 age and sex-matched (17 males and 24 females) normal AA controls. All subjects had clinical evaluation, resting 12-lead electrocardiography (ECG), 12 minutes self-paced walking exercise, and were tested for haematological and biochemical abnormalities. The clinical features of the patients reflected a hyperdynamic circulation which was evidenced by faster heart rates, wide pulse pressure, cardiomegaly, loud heart sounds and cardiac murmurs. Non-specific ECG findings were observed in this study. The mean QRS voltage (Sokolow-Lyon criteria) was significantly higher in patients compared to controls (P < 0.05). The mean rate, P wave duration and corrected QT interval of SS patients were significantly higher than the controls. The patients also had a significantly lower mean QRS frontal axis than the controls (P < 0.05) but there was no difference between the two groups in the mean QRS duration and PR interval. There was no abnormal QRS axis in the two groups. The self-paced walking exercise test showed significant limitation of exercise capacity in SCA patients, as evidenced by the significant reduction in speed and distance covered by the patients compared with the controls. While both groups achieved similar post exercise heart rate and systolic BP, the change in heart rate was significantly less in the patients. This study concluded that SCA patients have larger hearts and non-specific ECG changes. They showed significant limitation of exercise capacity with self-paced walking exercise, which was a safe and reproducible measure of cardiac reserve in them.