The effect of stress management and relaxation with guided imagery on upper respiratory tract infections (URTIs) was investigated in 45 children with a history of 10 or more infections in the past year. To investigate the influence of psychological treatment on mucosal immunity, secretory immunoglobulin A (sIgA) was measured before and during treatment. The number of symptomatic episodes during 13 weeks of monitoring was similar in treatment and waitlist conditions; however, episodes were shorter in stress management and guided imagery conditions than in the waitlist condition. Levels of sIgA increased toward the end of treatment. These findings were confirmed in a replication study. In addition, symptom reduction and improvements in psychological state persisted at 1-year follow-up. The findings suggest that psychological treatment interrupts a chronic illness cycle in children with symptoms of recurrent URTI.