To assess the associations between a doctor diagnosis of asthma and wheezing (independent of a diagnosis of asthma) with sickle cell disease (SCD) morbidity, we conducted a retrospective review of Emergency Department (ED) visits to the Mount Sinai Medical Center for SCD between 1 January 2007 and 1 January 2011. Outcomes were ED visits for pain and acute chest syndrome. The cohort included 262 individuals, median age 23·8 years, (range: 6 months to 67·5 years). At least one episode of wheezing recorded on a physical examination was present in 18·7% (49 of 262). Asthma and wheezing did not overlap completely, 53·1% of patients with wheezing did not carry a diagnosis of asthma. Wheezing was associated with a 118% increase in ED visits for pain (95% confidence interval [CI]: 56–205%) and a 158% increase in ED visits for acute chest syndrome (95% CI: 11–498%). A diagnosis of asthma was associated with a 44% increase in ED utilization for pain (95% CI: 2–104%) and no increase in ED utilization for acute chest syndrome (rate ratio 1·00, 95%CI 0·41–2·47). In conclusion, asthma and wheezing are independent risk factors for increased painful episodes in individuals with SCD. Only wheezing was associated with more acute chest syndrome.