Background: Clinical experience suggests an association between stressful life events and fluctuations in symptom severity of tic disorder patients. The aim of the present study was to examine this possible relationship in a prospective longitudinal design. Method: Two groups of patients with tic disorder according to the research criteria of the Tourette Syndrome Classification Study Group were included in this study (Sept. 2001 through March 2002): a pediatric group aged from 7 through 16 years (N = 25) and an adult group aged 18 years and older (N = 32). During a 12-week period, participants were asked weekly to fill out questionnaires regarding the occurrence of small life events and self ratings of tic severity. Results: Twenty-four of 25 patients in the pediatric group completed the study, and 28 of 32 patients in the adult group completed the study and reported at least 1 life event. In the adult group as a whole, we found a weak but statistically significant correlation between negative small life events and tic severity during the same week (r = 0.268, p <.001). However, only a minority of individual pediatric (21%) and adult (18%) patients demonstrated significant relationships between the frequency of small life events and tic severity in the same week or 1 week later (p less than or equal to .05), with undesirable small life events positively associated with tic severity in some patients and negatively associated with tic severity in other patients. Conclusion: Contrary to traditional views, in general, life events do not account for changes in tic severity. Only in a minority of tic disorder patients do fluctuations in symptom severity appear to be associated with possibly stressful small life events