American Urology Association has developed a 7-item instrument I-PSS to measure the signs and symptoms of the disease process of BPH. The instrument was validated for a one-month and later for a week recall. Early and faster relief of symptoms are extremely important to patients.Therefore, we validated I-PSS for as early as 2 to 5 day response. OBJECTIVE: To test the reliability and validity of I-PSS administered between day two to five post-treatment. METHODS: I-PSS was administered at baseline and at day 2-5 after treatment as part of a double-blind study with 674 symptomatic BPH subjects. The patient s were also administered a single item global question about their urinary condition. The test-retest reliability of the 2-5 day version was evaluated with intra-class correlation coefficient (ICC) between the two assessments. Internal consistency was computed with Cronbach s ?. Guyatt s responsiveness statistics was estimated. Factor content of day 2 to 5 I-PSS was examined. The ability of I-PSS scores at day 2-5 to discriminate between improved and unimproved subjects was tested with receiver s operating characteristics curve (ROC) analysis. RESULTS: The average measure of ICC was found to be 0.7414. Cronbach s ? was estimated to be 0.8093 (Barry et. al (1995) reported 0.74 for ICC and 0.67 for Cronbach s ? for one-week I-PSS). The Guyatt s responsiveness statistic was found to be 1.04 as compared to 0.82 for one-week version. Factor analysis revealed only one underlying factor (urinary symptoms) with an eigenvalue greater than one. The areas under ROC curve was 0.7635 (0.74 reported for one-week version). CONCLUSIONS: The results conclude that I-PSS can be used to evaluate day 2-5 symptoms for BPH.