In acute stroke patients, anger can disturb management and rehabilitation and creates a stressful situation for family, health-care providers and other patients. We aim to describe the presence of anger and its association with demographic, clinical, psychiatric, lesion variables and functional outcome in acute stroke patients. We screened anger prospectively in 202 consecutive acute stroke patients (< or =4 days) using eight items from three psychiatric scales (Catastrophic Reaction Scale, Mania Rating Scale and Comprehensive Psychopathological Rating Scale). Anger was present if the patient scored in at least one item. Anger was detected in 71 (35%) patients and 26 of these were severely angry (> or =4 points). There was no association between anger and the considered variables. Analysis of the items extracted two factors: (i) the emotional-cognitive and (ii) the behavioural components of anger. These components were independent of each other in 26 patients. In 38 patients we found a dissociation between clinical observation and patients' subjective expression. Anger was frequent in acute stroke patients. Anger was probably triggered by the brain lesion, which interfered with the emotional control. The lack of an association with clinical and imaging variables suggests a contribution of psychological/psychosocial dimensions.