Myocardial ischemia (MI) in children living with sickle cell anemia (SCA) is rarely reported. MI among children living with this disease could portend untoward outcomes on their quality of life and survival. This study evaluated the prevalence and associated risk factors of MI in children living with SCA during a vaso-occlusive crisis (VOC) compared with those with SCA who had no symptoms nor an MI in the past (those in “steady state”) in Lagos, Nigeria. This comparative cross-sectional study was conducted over 10 months (between March and December 2019) among 250 children living with SCA aged 6 months–18 years (125 in VOC and 125 age and sex-matched controls in steady state). The assessment of MI was determined by measuring cardiac troponin T (cTnT) and electrocardiography (ECG). The prevalence of MI measuring cTnT alone in children with SCA during VOC and steady state was 42.4% and 23.2%, respectively. Comparatively, measuring ECG alone, the prevalence of MI in VOC and steady state was 40.8% and 20.8%, respectively. The prevalence of MI measuring cTnT and ECG in children with SCA in VOC and steady state was 38.4% and 20%, respectively. Older age, severity of pain, longer duration of illness, frequent crises per year, elevated white blood cells, and platelet count were significantly associated with MI in participants with SCA. However, with multivariate analysis, age, severity of pain, and elevated platelet counts remained significantly associated with the occurrence of MI. This study affirms the high prevalence of MI in children with SCA irrespective of the diagnostic criteria. Routine evaluation should be done in this cohort to avert MI-associated sequelae.