Event-based prospective memory (PM) refers to the ability to remember to perform a delayed and intended action when an event is encountered in the future. Whether emotional targets promote PM performance is still controversial. The reason for these inconsistent findings may be related to the degree of target arousal and context valence (the valence of ongoing task trials) in the previous studies. This study aimed to investigate the separate and combined effects of target valence, arousal, and context valence on event-based PM through two experiments. The results showed that the participants were faster and more accurate in responding to positive, negative, and high-arousal PM targets. Interestingly, an interaction effect of target valence, arousal, and context valence was observed, implying that their individual effects on PM performance cannot be understood in isolation. These findings demonstrate that positive, negative, and high-arousal PM targets can enhance PM performance. In addition, the results provided support for both the emotion enhancement account and the emotion-saliency account, depending upon whether the valence of the PM target matched or did not match the valence of the context. Moreover, context valence can modulate the effect of arousal on PM across different target valences.