Abstract Science-related populism is often used to undermine public trust in science. Good scientific practice contributes to public trust in science, whereas misconduct promotes public skepticism. Since research ethics are a vital part of research integrity, we argue that ethical misconduct potentially undermines trust in scientists, particularly among people with populist beliefs. Drawing on a quota sample of German citizens (N = 1,321), the experimental study examines the influence of ethical conduct on trust in scientists, moderated by science-related populist beliefs. More specifically, we tested the influence of experimental deception (with and without debriefing) using a vignette design. The results of our study showed that ethical misconduct is negatively associated with trust in scientists. In addition, the relationship between ethical misconduct and trust in scientists was influenced by both science-related populist beliefs and science literacy. Although people with high science-related populist beliefs generally placed less trust in scientists, the negative effect was even more pronounced for people with low science-related populist beliefs. Our findings further revealed that ethical misconduct reduces trust in science among people with both low and high science literacy. This demonstrates the importance of researchers transparently discussing and reflecting on ethical research conduct to promote trust in scientists.