The goal of this research was to create a self-report measure of relational boredom using a prototype approach. In the first study, 2 samples (participants in dating relationships and in marital relationships) generated features of the concept of relational boredom. In Study 2, these features were rated for prototypicality by 2 samples (dating and married). A Relational Boredom Scale was constructed by selecting those features (items) that were rated as most central to the construct. In Study 3, the reliability and validity of the scale were assessed, again with participants in dating and marital relationships. There was evidence that the Relational Boredom Scale is a psychometrically sound measurement instrument.