BACKGROUND: Steroid therapy has been considered as co-analgesic for palliative treatment of metastatic bone pain in terminal cancer. We designed prospective study to observe analgesic efficacy of dexamethasone, to evaluate different analgesic assessment methods and its correlation to actual improvement of quality of life. METHODS: Thirty seven men with symptomatic bone pain of prostate cancer were treated with dexamethasone infusions (10mg twice a day) for 2 weeks. Response to treatment was assessed by daily analgesic intake, by the McGill-Melzack pain questionnaire (MPQ), and by a series of 17 linear analog self-assessment scales (LASA) relating to pain and to various aspects of quality of life. Biochemical and radiological markers were measured. RESULTS: Fourteen patients (38%) had improvement in indices used to assess pain at 2 weeks after starting dexamethasone. Reduction in pain indices was associated with improvement in other dimensions of quality of life and in the scale for overall well-being. Even though radiological and biochemical markers showed no correlation, symptomatic relief of pain was associated with a decrease in serum concentration of adrenal androgens. CONCLUSION:g We conclude that 1) dexamethasone treatment may cause useful relief of pain in some of patients with bone pain of prostate cancer; 2) this relief of pain is associated with suppression of adrenal androgens; 3) measures of pain and quality of life can be used to assess benefits of systemic therapy with dexamethasone; and 4) this effects of dexamethasone should be further investigated in bone pain of other metastatic cancer.