["What's known on the subject? and What does the study add? High grade prostatic intraepithelial neoplasia (HGPIN) is a risk factor for prostate cancer (PCa), but only multifocality is an indication for early rebiopsy. Other risk factors for PCa development from HGPIN remain unknown. PCa is related to testosterone. Testosterone has been proven to be linked to PCa detection and poor prognosis PCa. This study shows that low free and bioavailable testosterone levels are associated with an increased risk of PCa in a rebiopsy after HGPIN diagnosis. Men with low testosterone levels and HGPIN could therefore be considered a high-risk cohort for developing PCa.", 'To determine the relevance of the hormonal profile of patients with high grade prostatic intraepithelial neoplasia (HGPIN) and its relationship to prostate cancer (PCa) in rebiopsy.', 'We prospectively analysed 82 consecutive patients with a diagnosis of HGPIN without PCa in a prostate biopsy between September 2007 and December 2009. Of these 82 patients, 45 underwent rebiopsy and their hormonal profile was determined (testosterone and sex hormone-binding globulin [SHBG]) as part of our clinical protocol. Patient age, PSA level, prostate volume, PSA density, testosterone, free testosterone, bioavailable testosterone and SHBG were recorded prospectively. A comparative study between those patients with a positive rebiopsy and those with a negative rebiopsy was performed.', 'We found that free testosterone (P = 0.04), bioavailable testosterone (P = 0.04) and SHBG (P = 0.02) were significantly associated with a positive rebiopsy. Other variables such as age (P = 0.745), PSA level (P = 0.630), prostate volume (P = 0.690), PSA density (P = 0.950), testosterone (P = 0.981) and prostatic intraepithelial neoplasia multifocality (P = 0.777) were not associated with the presence of adenocarcinoma in the rebiopsy.'] Does low testosterone level predict prostate cancer in re-biopsy in patients with high grade prostatic intraepithelial neoplasia?