The purpose of this research was to develop and validate a new instrument to assess the regulation of anger and sadness in interpersonal situations, covering a wide range of emotion regulation strategies. Two studies were carried out, both of them using purposively selected samples. In Study 1 we created a set ofitems based on previous studies of emotion regulation, applied a preliminary version of this scale to a pilot sample of undergraduate students (n = 400), and then selected, using exploratory factor analysis (EFA), the best 28 items to include in a brief version of the instrument, the Scale of Emotion Regulation in Interpersonal Situations (SERIS). In Study 2 we tested the resulting scale ina new sample of undergraduate students (n = 259) by means of confirmatory factor analysis. Study 2 validated the factor structure identified in the EFA. Results showed that the scale has adequate internal consistency and psychometric properties. The new scale also identifies the strategies that are most frequently used in the anger and sadness scenarios, showing differential patterns which are consistent with previous literature on emotion regulation. We discuss the limitations of the study and acknowledge that future studies addressing the scale's convergent and discriminant validity are now required.