The present study examined the relationship between dyadic interaction patterns and implicit theories of relationships (ITRs; deeply held beliefs about the nature of relationships) using a sample of N = 104 couples. We hypothesised that destiny beliefs would predict greater avoidance in conflict interactions, while growth beliefs would predict more constructive communication. Surprisingly, the results of the current study challenge the existing literature by indicating that neither destiny nor growth beliefs predict constructive communication or mutual avoidance for the couple. Further, while destiny beliefs were related to increased withdrawal in a demand-withdraw pattern, growth beliefs related to both demand and withdraw in a demand-withdraw pattern. These findings suggest that assessing the relationship between ITRs and communication patterns at the couple level introduces complexity that is underexplored in the current literature on implicit theories of relationships.