Young adults' romantic relationships are often unstable, commonly including breakup--reconcile patterns. From the developmental perspective of emerging adulthood exploration, such relationship "churning" is expected; however, minor conflicts are more common in churning relationships. Using data from the Toledo Adolescent Relationships Study ("N" = 792), the authors tested whether relationship churning is associated with more serious conflict, such as physical violence and verbal abuse. Couples who were stably broken up (breakup only--no reconciliation) were similar to those who were stably together in their conflict experiences. In contrast, churners (i.e., those involved in on/off relationships) were twice as likely as those who were stably together or stably broken up to report physical violence and half again as likely to report the presence of verbal abuse in their relationships; this association between churning and conflict held net of a host of demographic, personal, and relationship characteristics. These findings have implications for our better understanding of unhealthy relationship behaviors. (Contains 3 tables and 1 note.)