Hypovitaminosis D is a common vitamin deficiency in the general population. The objective of this study was to investigate potential associations between vitamin D deficiency, physical functioning, and behavioral health variables in a population of chronic pain patients. Serum vitamin D levels were collected at admission from 162 consecutive patients admitted to the Mayo Clinic Comprehensive Pain Rehabilitation Center. Patients with vitamin D deficiency (£ 20 ng/ml) were compared to patients who were not deficient (>20ng/ml) on demographics, pain duration, pain severity, body mass index (BMI), exercise tolerance, and muscle strength. Perceived general health was assessed using the MOS-SF-36. The mean age was 47.6 years (SD=13.0). Seventy-nine percent (n=128) of patients were female and 97% (n=158) were Caucasian. The mean pain duration upon admission was 10.8 years (SD=13.1). The mean vitamin D serum level was 29.2 ng/ml (SD=12.0) and hypovitaminosis D was found in 24.7% (N=40) of patients. No significant differences in demographics, pain severity, or pain duration were identified between the two groups (p>.05). The patients in the non-deficient group demonstrated significantly greater exercise tolerance (p<.05) compared to the vitamin D deficient group. No differences were detected in muscle strength or BMI (p>.05). The vitamin D deficient group reported lower levels of general health perception (p<.05) compared to the non-deficient group. In this consecutive series of chronic pain patients, hypovitaminosis D was highly prevalent. Reduced exercise tolerance and poor health perception may be indicative of physical and general health behaviors that increase the risk of developing vitamin D deficiency in this patient population. Further research is needed to clarify the risk factors and clinical correlates of hypovitaminosis D among patients with chronic pain.