The error‐related negativity (ERN), an ERP elicited immediately after errors, is enlarged among individuals with anxiety. The relationship between anxiety and enlarged ERN has spurred interest in understanding potential therapeutic benefits of decreasing its amplitude within anxious individuals. The current study used a tailored intervention—expressive writing—in an attempt to reduce the ERN among a sample of individuals with chronic worry. Consistent with hypotheses, the ERN was reduced in the expressive writing group compared to an unrelated writing control group. Findings provide experimental support that the ERN can be reduced among anxious individuals with tailored interventions. Expressive writing may serve to “offload” worries from working memory, therefore relieving the distracting effects of worry on cognition as reflected in a decreased ERN.