Asthma is associated with decreased health-related quality of life and increased physical comorbidity and mortality, high rates of clinic visits and hospitalizations, and loss of productivity in the workplace.The objective of the present study was to determine the joint effect of psychological distress and asthma on functional disability in a community sample.The authors used data from The Canadian Community and Health Survey (N=62,274). Psychological distress was measured by the 10-item Kessler (K-10) instrument. Asthma, disability days, self-assessed health status, and long-term reduction in activities were assessed by personal interview.The prevalence of functional disability was higher in subjects with asthma and comorbid psychological distress than in individuals with either asthma or psychological distress alone.Detecting and managing psychological problems might be particularly beneficial for persons with asthma.