Few studies have simultaneously looked at the relative contribution of positive and negative behaviors to understand relationship outcomes. This study examined the relative roles of perceived partner support and psychological aggression in two relationship outcomes-relationship satisfaction and the willingness to invest in the relationship-as well as the contribution of attachment anxiety as a moderator in 307 couples seeking relationship therapy. Path analyses revealed that perceived partner support was associated with individuals' own higher relationship satisfaction and willingness to invest in the relationship. Attachment anxiety moderated these associations. Perceived partner psychological aggression was not associated with relationship outcomes.