['Patients who suffer from mental fatigue after a stroke or traumatic brain injury (TBI) have a drastically reduced capacity for work and for participating in social activities. Since no effective therapy exists, the aim was to implement a novel, non-pharmacological strategy aimed at improving the condition of these patients.', 'This study tested a treatment with mindfulness-based stress reduction (MBSR). The results of the programme were evaluated using a self-assessment scale for mental fatigue and neuropsychological tests. Eighteen participants with stroke and 11 with TBI were included. All the subjects were well rehabilitated physically with no gross impairment to cognitive functions other than the symptom mental fatigue. Fifteen participants were randomized for inclusion in the MBSR programme for 8 weeks, while the other 14 served as controls and received no active treatment. Those who received no active treatment were offered MBSR during the next 8 weeks.', 'Statistically significant improvements were achieved in the primary end-point--the self-assessment for mental fatigue--and in the secondary end-point--neuropsychological tests; Digit Symbol-Coding and Trail Making Test.'] Does mindfulness-based stress reduction ( MBSR ) improve long-term mental fatigue after stroke or traumatic brain injury?