Indoor environment factors have been associated with risk of asthma exacerbations in children but little is known about their role on asthma hospital readmissions. As children in Western societies continually spend more time indoors, understanding the influence of these factors on asthma exacerbation is important. We examined the role of indoor environmental and lifestyle characteristics on child asthma readmissions.A hospital-based case-control study recruited 22 children readmitted for asthma and 22 controls not readmitted for asthma. Logistic regression models were used to examine the association between aeroallergens and fungi in the bedroom and indoor lifestyle characteristics factors for asthma readmissions. To determine the best possible set of predictors among a large set of risk factors, we used random forests (RF) techniques.Higher levels of airborne Cladosporium and yeast in the child's bedroom increased risk of readmission (OR = 1.68, 95% CI 1.04-2.72 and OR = 1.52, 95% CI 0.99-2.34, respectively). Carpeted floors in the bedroom and synthetic doonas were also associated with increase in asthma readmissions (OR = 4.07, 95% CI 1.03-16.06 and OR = 14.6, 95% CI 1.26-169.4, respectively). In the home, frequent vacuuming using bagged cleaners increased risk of asthma readmission OR = 15.7 (95% CI 2.82-87.2).Factors in the child's bedroom play an important role in increasing the risk of asthma hospital readmissions. These findings have major clinical implications as the identified potential risk factors may be modifiable. Further epidemiological studies with larger samples are necessary to evaluate these associations further.