The present study examined measurement invariance of trait anger with respect to age. In addition, age-related differences in latent variables (factor variances, factor covariances, and factor means) were investigated. A sample of 1216 participants, divided into six age groups, ranging from under 30 to over 70 years, was tested using the angry temperament and angry reaction scales from the State-Trait Anger Expression Inventory (STAXI; Spielberger, 1988). Results show that strong measurement invariance held across the six age groups. For both angry temperament and angry reaction, factor variances tended to decrease into middle age and then increase again into old age. Factor correlations decreased into old age, implying a differentiation of trait anger. Finally, regarding factor means, older adults showed less anger than younger adults, suggesting higher levels of self-regulation or less exposure to anger-provoking contexts in later life. (C) 2011 Elsevier Ltd. All rights reserved.