Chronic fatigue syndrome is characterized by severe, persistent fatigue which is not relieved by rest and is not associated to other medical conditions. Other common symptoms are including concentration and memory impairment, muscle and multiple joints pain, extreme exhaustion after physical or mental exertions, irritable bowel syndrome-like symptoms and depression, anxiety, mood swings and panic attacks. Etiology of the syndrome is not yet clear, post-viral and stress hypotheses were not verified. Diagnosis is confirmed in case of new onset of severe fatigue, for six consecutive months or more; fatigue is leading to significant reduction of the activity levels and is accompanied by other four or more of the specific associated symptoms, which are also lasting for six months or longer. The management of the disease is based on cognitive behavioral therapy, graded exercise therapy and pacing; medication plays a minor role in therapy. The occupational status is severely affected, more than half of the cases being unable to work. Full recovery rate is in average of about 5%.