OBJECTIVES: To determine the socioeconomic predictors of asthma control in children, as defined by the Canadian Pediatric Asthma Consensus Guidelines (CPACG). METHODS: A cross-sectional design was used to analyze data from a completed CIHR-funded study based on 879 children from seven sites in the Greater Toronto Area between 2000-2003. Children were aged 1 to 18 years with a documented diagnosis of asthma and a prescription for an asthma medication in the previous year. Multiple linear regressions were used to analyze asthma control based on six equally weighted control parameters (daytime symptoms, night-time symptoms, need for beta2-agonists, physical activity level, exacerbations, and school absences). The impact of the following factors was investigated: family income adequacy, parent education, parent employment, ethnicity, parent immigration, language, parent marital status, and physical environment characteristics. The CPACG and Global Initiative for Asthma (GINA) guideline definitions of asthma control were compared. RESULTS: Only 11% of patients met the requirements for acceptable control by satisfying all six parameters, while 20% satisfied five parameters, and 69% satisfied four or fewer parameters. The multiple regressions indicated that income adequacy had an impact on asthma control. Children from families in the middle income adequacy quintile tended to have worse control. Higher numbers of asthma triggers, increased physician or specialist visits, and daily use of anti-inflammatories, were associated with lower levels of control. The CPACG and GINA guidelines had a high level of agreement (Weighted kappa=0.74, p<.0001), although it was more difficult to achieve acceptable asthma control in the CPACG guidelines. CONCLUSION: Despite the established effectiveness of inhaled corticosteroids in the prevention of asthma exacerbations, poor control remains a problem which was affected by family income adequacy.