Undergraduate research is lauded as a high-impact practice owing to the array of benefits that students can reap from participating. One unexplored construct that may affect student intent to persist in research is research anxiety, defined as the sense of worry or apprehension associated with conducting research. In this study, we surveyed 1272 undergraduate researchers across research-intensive, master's-granting, and primarily undergraduate institutions to assess the relationship among student demographics, research anxiety, and intent to pursue a research career. Using structural equation modeling, we identified that women and students with higher grade point averages (GPAs) were more likely to report higher levels of research anxiety compared with men and students with lower GPAs, respectively. Additionally, research anxiety was significantly and negatively related to student intent to pursue a research-related career. We coded students' open-ended responses about what alleviates and exacerbates their anxiety and found that experiencing failure in the context of research and feeling underprepared increased their research anxiety, while a positive lab environment and mentor--mentee relationships decreased their anxiety. This is the first study to examine undergraduate anxiety in the context of research at scale and to establish a relationship between research anxiety and students' intent to persist in scientific research careers.