Beta-endorphin/beta-lipotropin immunoreactivity (BE/BLPH-IR) content was evaluated in the CSF of patients suffering by deafferentation pain syndromes. BE/BLPH-IR CSF concentrations of these patients were compared with those obtained in a group of patients affected by low back pain and in a control group without pain problems. No statistically significant variation in BE/BLPH-IR levels were found between controls and subjects with different types of chronic pain.