The (participatory) opportunities provided by interactive features on news sites have been widely theorized and investigated in recent years. However, user comments’ ef-fects on the perception of journalistic quality have only begun to be examined. To investi-gate those effects, the present study deployed two 2 × 2 experiments with a between-sub-ject design, thereby exposing participants (N = 224) to a constructed online news article (covering a potential military intervention of the German armed forces against ISIS) and corresponding user comments. Comments varied in terms of (I) support for the issue de-scribed in the article as well as the (II) addressing of journalistic quality criteria (accuracy, impartiality). Results indicate that user comments indeed had considerable effects on readers’ quality assessments. If anonymous users praised the quality of the article in their comments, journalistic quality was perceived to be significantly higher. Implications for news media and media effects research are discussed.