OBJECTIVE: To investigate the emotional and neurobehavioural status of patients suffering from chronic pain. METHODS: Fifteen male patients with chronic lower back pain and 15 healthy control subjects were studied for approximately six months. Pain was measured using a visual analogue scale. The WHO Neurobehavioral Core Test Battery (NCTB) was used to assess neurobehavioural effects of environmental and occupational exposures. RESULTS: Visual analogue scale results demonstrated a modest range of reported pain (mean [+/- SD] 62.0 +/- 10.8) in chronic pain patients, whereas control subjects reported no measurable pain. With the NCTB, it was found that scores of negative mood state, including anger-hostility, depression-dejection, fatigue-inertia and tension-anxiety in pain patients were significantly higher than scores in the control subjects. By contrast, scores of positive mood state (vigour-activity) in chronic pain patients were lower than those in the control group. The NCTB scores of the Santa Ana Dexterity and Pursuit Aiming II tests in chronic lower back pain patients were lower than those of the control group. Scores for other NCTB subtests, including the Digit Span, Benton Visual Retention and Digit Symbol tests, were not significantly different compared with controls. CONCLUSIONS: Chronic lower back pain patients had more negative mood and less positive mood than controls. These patients also demonstrated neuromotor deficits in coordination and reaction time. Further studies are required to examine possible neurological mechanisms and research potential intervention strategies for patients suffering from chronic pain.