ObjectiveTerror management theory posits that when mortality is salient, individuals attempt to defend their cultural worldviews. Although numerous studies have confirmed this hypothesis, some recent studies have suggested that East Asians do not engage in worldview defense. We conducted a pre-registered experiment with 895 Japanese adults to investigate whether they exhibited worldview defense at an unconscious level. Participants performed the Implicit Association Test using Japanese and Korean surnames as stimuli after being primed with thoughts about mortality.ResultsThe results revealed that mortality salience had no influence on implicit ethnic bias. These findings support the notion that East Asians do not engage in worldview defense, in accord with recent criticism of the validity of terror management theory. We discuss the limitations and implications of our findings.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13104-023-06360-9.