Worry has been experimentally linked to a range of cognitive consequences, including impairments in working memory, inhibition, and cognitive control. However, findings are mixed, and the effects of worry on other phenomenologically-relevant constructs, such as sustained attention, have received less attention. Potential confounds such as speed-accuracy tradeoffs have also received little attention, as have psychometric and related design considerations, and potential moderators beyond trait worry. The present study investigated the effects of experimentally-induced worry versus a neutral control condition on speed-accuracy tradeoffcorrected performance on a validated measure of sustained attention (88 participants; withinsubjects). Moderation by trait worry and trait mindfulness was probed in confirmatory and exploratory analyses, respectively. Worry led to faster and less accurate responding relative to the neutral comparison condition. There was no main effect of condition or trait worry on sustained attention after accounting for speed-accuracy tradeoffs. In exploratory analyses, higher trait mindfulness was robustly related to better post-worry performance, including after controlling for trait worry, general distress, and post-neutral performance, and correction for multiple comparisons. Follow-up analyses exploring dissociable mindfulness facets found a robust relationship between present-moment attention and post-worry performance. Future research should experimentally manipulate mindfulness facets to probe causality and inform treatment development.