To determine whether repeat biopsy is necessary when the diagnosis of high-grade prostatic intraepithelial neoplasia (HGPIN) is made with a 12-core biopsy. Repeated biopsy has been recommended for individuals with HGPIN noted on sextant prostate biopsy because of the high likelihood of cancer detection. Recently, we have recommended the routine use of 12 cores, rather than 6, to improve cancer detection.