Previous studies have shown that psychopathy, one of the Dark Triad personality traits, is associated with relationship dissatisfaction. However, the similarity of psychopathy among romantic couples remains uncertain with regard to relationship outcomes. This study examined the effect of the perceptual similarity of psychopathy on marital quality in a sample of 245 heterosexual married couples, using intraclass correlation coefficients as the method for assessing couples' similarity. This study also explored the possible mediating role of couple communication based on the Actor-Partner Interdependence model. The results reveal that husbands' self-rating and wives' partner-rating of psychopathy showed negative effects on marital quality, whereas wives' perceptual similarity of psychopathy exerted both actor and partner effects on marital quality via couple communication. The current study enriches the theoretical framework of personality and relationship outcomes and emphasizes the importance of communication in a close relationship.