Sickle cell disease (SCD) is a genetic blood condition that places youth at increased risk for deficits in complex attention suggestive of increased risk for Attention-Deficit/Hyperactivity Disorder (ADHD). We used systematic screening to assess the prevalence of ADHD in a clinic-based sample of youth with SCD and explored factors related to ADHD. Caregivers of 107 children with SCD (ages 7-11 years) completed routine psychosocial screening which included inattentive symptoms of ADHD. Follow-up diagnostic procedures were completed for patients with elevated inattentive symptoms to assess for ADHD diagnoses. Biomedical and social-environmental variables were examined from the screening and medical records. Twenty-six percent of patients showed elevated inattentive symptoms with 13% meeting diagnostic criteria for ADHD diagnoses. Most children (75%) who met criteria for ADHD had not been previously diagnosed. Disease severity did not predict inattentive symptoms or ADHD diagnoses, though a measure of chronic inflammation was associated with ADHD. Family functioning was related to elevated inattentive symptoms but not ADHD diagnoses. Children with SCD show relatively high rates of ADHD with many cases not detected through routine care. Screening for ADHD as part of hematology care may be a feasible strategy to improve identification and access to intervention.