validity and reliability of persian version of international prostate symptom score

background: in order to use international prostate symptom score (ipss) in the iranian population, a valid and reliable persian version of this questionnaire is required. to date, this version of ipss with those characteristics is not available. material and methods: for evaluation of the validity, the original version of ipss (english version) was translated into persian and after 3 weeks was re-translated from persian to english.   the new english form was then compared with the original english ipss form. internal consistency was calculated. for measurement of reliability, the persian version of ipss was used to interview 50 patients with benign prostatic hyperplasia (bph). the difference between results was analyzed with a 3 week interval. results: there was no significant difference between english translations and internal consistency was 0.7 using cronbach’s α test.  test-retest reliability was assessed and showed no significant difference between the scores before and after 3 weeks (p value= 0.9). conclusion: persian version of ipss was proved to be valid and reliable and can be used as a symptom-based questionnaire for bph in iranian population.