This research aimed at validating two self-report composite rating scales of core affect that are useful when quick assessments are required, for instance, of current mood or recalled, anticipated, and experienced emotional reactions. The ratings were derived from the Swedish Core Affect Scales (SCAS) comprising six self-report rating scales of the two orthogonal dimensions of core affect, valence (unpleasantness-pleasantness) and activation (quietness-excitement). In three samples of university students who were requested to rate current moods, affect-inducing sounds, or affect-inducing pictures, the composite ratings were compared to SCAS, two widely used graphical rating scales of valence and activation, and skin conductance responses and the acceleratory peak of heart rate. Three different rating formats were also compared. The results showed that the composite ratings were reliable and yielded the expected correlations with the other ratings and with the physiological affect indicators. No effects of rating format were detected. It is concluded that the composite ratings of valence and activation may be used if quick assessments are called for. Choices can be made of any of three rating formats depending on purpose with the assessments.