OBJECTIVES: To determine whether treatment related pain reduction on the short- and long-term is predicted by different baseline variables, and with different accuracy, in patients with chronic low back pain as compared with those with chronic neck pain. DESIGN AND METHODS: A single blinded prospective cohort study based on patients with chronic musculoskeletal pain in the lower back (N = 167) or the neck (N = 136) who completed a 4-week multimodal rehabilitation program. At admission, each patient was evaluated on 17 potential predictors, including pain characteristics and physical, sociodemographic, and psychosocial-behavioral variables. Changes in self-reported pain intensity in the lower back or the neck between the pretreatment evaluation and those performed immediately after, and 12 months after the rehabilitation program, were assessed. RESULTS: Logistic regression models revealed that change in pain intensity could be predicted with good specificity but with poor sensitivity both for patients with chronic low back pain and chronic neck pain. Significant predictors among the neck pain patients were high endurance, low age, high pain intensity, few other symptoms, low need of being social, to do things with others, and to be helped, along with optimistic attitudes on how the pain will interfere with daily life. Among the low back pain patients, high pain intensity, low levels of pain severity, and high affective distress were important predictors. Variables such as sex, sick leave history, working status, accident, pain duration, and depressive symptoms demonstrated no predictive value. Short- and long-term pain outcome was equally predictable and predicted by almost the same variables. CONCLUSIONS: Patients who reported unchanged or increased pain after multimodal treatment could be predicted with good accuracy, whereas those who reported decreased pain were more difficult to identify. Treatment-related pain alteration in chronic low back pain seems to be predicted by partly different variables than in chronic neck pain