In an experiment with 109 undergraduates, we examined the effect of mood, cognitive style, and cognitive ability on implicit learning in the Artificial Grammar (AG) and Serial Reaction Time (SRT) tasks. Negative mood facilitated AG learning, but had no significant effect on SRT learning. Rational cognitive style predicted greater learning on both tasks, but this effect on SRT was mediated by cognitive ability. SRT, but not AG learning was significantly correlated with Math and English scores on the ACT. These findings confirm and contradict previous research. The association of negative mood and rational cognitive style with AG confirms that AG learning is facilitated by systematic, bottom-up processing. However, the lack of converging evidence for the SRT task suggests that the tasks involve different aspects of implicit processing. Theoretical explanations and suggestions for future research are discussed.