To address the validity of a common procedure for assessing problem–solving communication behavior in marriage, this study investigated the extent to which communication behavior is influenced by the difficulty of the topic being discussed. Married couples engaged in a sequence of four videotaped problem–solving conversations, and the topics discussed in each conversation were coded for difficulty. Hierarchical linear modeling was used to investigate both proximal and distal influences on communication behavior. At the proximal level, couples did not change their communication behavior in response to changes in topic difficulty that occurred across the four conversations. At the distal level, couples experiencing conflict over a highly difficult topic reported low relationship satisfaction and used negative forms of communication behavior in all their problem–solving conversations, regardless of the issue being discussed. The relationship between topic difficulty and communication behavior was mediated by marital satisfaction.