Among adults with sickle cell disease (SCD), pulmonary complications are a leading cause of death. Yet, the natural history of lung function in adults with SCD is not well established. We conducted a retrospective cohort study of adults with SCD who had repeated pulmonary function tests performed over 20 years of age. Ninety-two adults were included in this cohort. Rate of decline in FEV1 for men and women with SCD was 49 cc/year (compared with 20-26 cc/year in the general population). Further studies are needed to identify factors which impact the rate of lung function decline in adults with SCD.