Research has shown that catastrophizing is related to increased depression and chronic pain. However, some researchers have questioned the utility of catastrophizing as a separate construct, suggesting that it may just be a symptom of depression. The present investigation used path analysis to determine if catastrophizing was related to McGill Pain Questionnaire scores when controlling for depression as assessed by the Beck Depression Inventory in a group of 85 chronic pain patients. According to Fields' model of the relationship between pain and depression, we predicted that catastrophizing would mediate the the relationship between depression and the evaluative and affective aspects of pain, but not the sensory aspect. The resulting path coefficients appear to support these predictions. The results suggest that catastrophizing is a separate construct which may impact on pain perception and treatment. The data also provide some support for Field's neurobiological model of the relationship between depression and pain.