Abstract Background Sleep-disordered breathing (SDB) may lead to poor asthma control in children. Objective To identify risk factors of SDB in children with asthma and assess its impact on asthma control. Methods In this cross-sectional study, we collected data of outpatients with asthma at the Children’s Hospital of Chongqing Medical University from June 2020 to August 2021. The Pediatric Sleep Questionnaire—Sleep-Related Breathing Disorder and the age-appropriate asthma control tests Childhood Asthma Control Test and Test for Respiratory and Asthma Control in Kids were completed. Results We enrolled 397 children with a male-to-female ratio of 1.7:1 and a mean age of 5.70 ± 2.53 years. The prevalence of SDB was 21.6%. Allergic rhinitis (odds ratio OR = 3.316), chronic tonsillitis (OR = 2.246), gastroesophageal reflux (OR = 7.518), adenoid hypertrophy (OR = 3.479), recurrent respiratory infections (OR = 2.195), and a family history of snoring (OR = 2.048) were risk factors for the development of combined SDB in children with asthma (p