A meta-analysis was conducted to examine the effects of exercise on anxiety. Because previous meta-analyses in the area included studies of varying quality, only randomized, controlled trials were included in the present analysis. Results from 49 studies show an overall effect size of -0.48, indicating larger reductions in anxiety among exercise groups than no-treatment control groups. Exercise groups also showed greater reductions in anxiety compared with groups that received other forms of anxiety-reducing treatment (effect size = -0.19). Because only randomized, controlled trials were examined, these results provide Level 1, Grade A evidence for using exercise in the treatment of anxiety. In addition, exercise dose data were calculated to examine the relationship between dose of exercise and the corresponding magnitude of effect size.