The main goal of this study was to examine the effect of written exposure on generalized anxiety disorder (GAD)-related symptoms in high worriers. Thirty nonclinical high worriers were randomly assigned to either a written exposure condition or a control writing condition. Self-report measures were used to assess worry, GAD somatic symptoms, depression, and intolerance of uncertainty at four time points during the study. Using hierarchical linear modeling (HLM), the authors found that all symptoms (i.e., worry, GAD somatic symptoms, and depression) significantly decreased over time in the written exposure group (although GAD somatic symptoms also decreased in the control group). Moreover, consistent with previous findings that intolerance of uncertainty preceded changes in worry over the course of treatment, intolerance of uncertainty scores predicted subsequent scores on all symptom measures in the experimental group. In contrast, worry and depression scores predicted subsequent intolerance of uncertainty scores in the control group. Writing Instructions are appended. (Contains 2 tables, 3 figures and 1 note.)