The perception and interpretation of pain is the end point of an interaction of cognitive, cultural, and envioremental factors and this complex interaction effects the pain response and quality of life of each person which shows that pain perception and the verbal and behavioral response shows variations and is specific for each patient. Chronic pain can be due to Fibromyalgia Syndrome (FMS) and Neuropathic Pain (NP) where the underlying pathophysiologic mechanisms are being revealed or it can be chronic low back pain (CLBP) where pain persists in spite of healing of tissue and no underlying pathologic mechanism can be defected. Central sensitization, inhibition of descending pain inhibitory systems, functional changes in otonomic nervous system amd neurotransmitter as well as changes in stres response system are factors contributing to the initiation and maintenance of pain and cognitive, behavioral factors are also important contributors in chronic pain. Biopsychosocial and biomedical mechanisms should be assessed in the rehabilitation interventions. The aims of rehabilitation in chronic pain are to increase activity tolerance, functional capacity and to decrease socio-economic loads. The targets of activity should be physical, functional and social. Psychologic based programs as cognitive-behavioral techniques and operant conditioning are also valid procedures in rehabilitation of chronic pain patients. Rehabilitation should be multidisciplinary and of long-term targeted to valid out-come for success.