The present study aims to develop a brief instrument to assess self-reported affective experiences, the Hedonic and Arousal Affect Scale (HAAS), rooted in the valence-arousal model of affect. Throughout four different studies, we found that: (1) the 12-item version showed a better goodness-of-fit than an initial longer version (Study 1; n = 259); (2) the two-dimensional model of affect (i.e., four-factor model: positive affect and high arousal, positive affect and low arousal, negative affect and high arousal, and negative affect and low arousal) showed the best fit to our data (Study 2; n = 525); (3) the HAAS showed evidence of concurrent validity with related measures in the field (Study 3; n = 480); and (4) it showed partial support for temporal invariance (Study 4; n = 262). The content and psychometric qualities of the HAAS make it a suitable brief scale to measure affect and could be particularly useful for repeated measures designs such as psychological interventions, experimental studies, or ecological momentary assessment studies. •Brief instrument (12 items) to assess self-reported affective experiences•Rooted in the valence-arousal model of affect•Concurrent validity with related measures and temporal invariance•Useful for repeated measures designs (e.g. interventions, experimental, diary)