Disability associated with headache cannot be fully accounted for by pain intensity and headache frequency. As such, a variety of cognitive and affective factors have been identified to help explain headache-related disability beyond that accounted for by pain levels. Pain-related anxiety, a multidimensional construct, also has been found to contribute to disability in headache sufferers. What is not known is whether pain-related anxiety is unique in contributing to disability beyond the role of headache-specific cognitive factors and emotional distress. The present study examines the influence of pain-related anxiety on disability, after controlling for pain, cognitive (self-efficacy and locus of control), and affective factors (emotional distress) in a sample of 96 primary headache sufferers. Pain, headache-related control beliefs, and emotional distress accounted for 32%, with locus of control related to health care professionals contributing unique variance. In the full model, with the addition of pain-related anxiety, only pain-related anxiety was a unique predictor of disability. These findings suggest that pain-related anxiety may have a unique and important role in contributing to disability in headache sufferers.