Aim: To identify and measure (neuro)physiological factors of fatigue in fatigued cancer survivors and to determine the role of these factors in the maintaining of fatigue. The identification of (neuro)physiological factors of persistent fatigue can help to improve the diagnostics of fatigue, predict therapy outcome and facilitate other treatment options. Finally, if (neuro)physiological characteristics of fatigue can be influenced by CBT it will enhance our understanding of the mechanism causing fatigue.