Background: Few studies have explored the metacognitive components of anger, and at present there is no metacognitive framework on anger incorporating both positive and negative beliefs about anger and distinct maladaptive processing routines, such as rumination. Aims: The aim of the present preliminary studies was to apply a metacognitive framework to anger and put forward a new anger self-report scale, the Metacognitive Anger Processing (MAP) scale, intended as a supplement to existing measures of anger disposition and to enhance anger treatment targets. Method: The new measure was tested in a nonclinical and a clinical sample together with measures of anger and metacognition to establish factor structure, reliability, concurrent, and convergent validity. Results: The MAP showed a reliable factor structure with three factors - Positive Beliefs about anger, Negative Beliefs about anger, and Rumination; good internal reliability, and test-retest reliability. The subscales showed positive correlations with anger and the pattern of correlation with the general metacognitive measure supported the idea that the MAP represents dimensions of metacognition as it relates to anger. Conclusions: The present data indicate that positive as well as negative beliefs are involved in the tendency to ruminate about angry emotions. Clinical interventions may benefit from an exploration of the patient´s experience of anger, as structured by the MAP's factors and their interrelationships. The psychometric properties of the MAP should be further investigated in clinical samples using larger test batteries and objective measures of aggression.