In the present research, three experiments were conducted to examine the effects of anger and sadness on spontaneous trait inferences (STIs). Using a probe recognition paradigm, Experiment 1 revealed that angry participants made more errors in response to probes following trait-implying behaviours than sad participants did. Using a false recognition paradigm, Experiments 2 and 3 revealed that angry participants made more errors in response to systematic pair trials than sad participants did. The three experiments provided convergent evidence that angry individuals were more inclined to form STIs than sad individuals were. The current research first demonstrated the different effects of specific negative mood states (anger vs. sadness) on STIs, providing further insight into the relationship between mood and STIs.