The literature about treatment of chronic fatigue syndrome (CFS) recommends psychoeducation of patients and their families as a powerful resource against discrimination of probands and worsening of symptoms as pain and fatigue. Cognitive and behavior therapies should be offered in order to help promoting regular physical activity of moderate intensity, identify and intervene upon psychological stressors and acceptance of CFS as a medical condition that allows opportunities for a significant and satisfactory life. It will be reported and discussed a brief behavior-analytic treatment of a 30-year-old woman living with CFS for five years. The discussion will emphasize the differential effect exerted upon respondent and operant behaviors related to pain, social withdrawal and occupational impairment or related to behavioral activation, social interaction and well-being.