Goals of Work. To examine the reliability between the Brief Pain Inventory (BPI) pain intensity and pain interference scores in patients with bone metastases. To also measure the correlation of pain interference with both Karnofsky Performance Score (KPS) and enjoyment of life. Patients and Methods. Patients with bone metastases receiving palliative radiotherapy for bone pain rated their intensity and interference of pain using the BPI before, 10 consecutive days after, and one month following treatment. All patients were prescribed 8 mg of dexamethasone prior to treatment in hopes of preventing a pain flare. Reliability was assessed in terms of internal consistency using Cronbach's coefficient alpha at baseline and follow-up. Spearman's correlation coefficient measured the correlation between pain interference and KPS or enjoyment of life at baseline. Main Results. Between January 2004 and October 2005, thirty-three patients (10 female and 23 male) were accrued. Twenty-two were available for one-month follow-ups. Over the 10-day followup, the average consistencies of worst, average and current pain were very similar (0.951, 0.952 and 0.949). For all pain scores, Cronbach's alphas began with lower baseline values and stabilized after the 5th day of follow-up. At one-month, the reliabilities remained similar for all pain intensities (0.950, 0.939, and 0.939). Current pain generally had lower reliability than the other pain intensity scales. KPS had strong correlation with normal work (r = -0.42), general activity (r = -0.41) and walking ability (r = -0.35). Enjoyment of life showed strong correlation with all other pain interference items measured. Conclusions. Based on 10-day and one-month post-treatment scores, the BPI provides good reliability between pain intensity and pain interference scores in patients with bone metastases.