Psychological factors can play a role in asthma symptoms and may play a role in how individuals manage asthma. Because poor self-management of asthma has been linked to poor outcomes, it is important to understand perceived control of asthma--the individual's perceived ability to deal with asthma and its exacerbations effectively. This study used data from an ongoing panel study of adults with asthma (n = 601). The 11-item Perceived Control of Asthma Questionnaire (PCAQ) demonstrated internal consistency (Cronbach's alpha = 0.74) and excellent construct validity, correlating strongly with asthma severity, quality of life, and Medical Outcomes Study Short Form (SF-36) measures of health status (p < 0.05). After controlling for demographics and asthma severity, each 6-point decrement in PCAQ score was significantly associated with increased risk of hospitalization (OR = 1.4 [95% CI: 1.1 to 1.8]), frequent activity restriction (OR = 1.5 [1.2 to 1.8]), and, among those with labor force participation (n = 551), asthma-related cessation of employment (OR = 1.7 [1.1 to 2.4]). The PCAQ is a short, easy to administer, reliable, and valid measure of perceived control of asthma. It is strongly associated with adverse asthma outcomes even taking into account demographic characteristics and asthma severity, suggesting that patient-centered interventions focusing on perceived control might improve asthma outcomes.