Localized prostate cancer is generally treated with radical prostatectomy or radiation therapy (external beam or brathytherapy). However, the primary treatment failure rate is especially high in so-called high-risk patients. Therefore, many clinical trials of neoadjuvant therapy before radiation therapy or prostatectomy have been conducted. We reviewed randomized controlled studies of neoadjuvant therapy combined with surgery or radiotherapy in localized or locally advanced prostate cancer. In some prospective studies, neoadjuvant hormones prior to external beam radiation therapy have been shown to significantly improve disease-free, disease-specific and overall survival as well as to reduce local recurrence or metastases. By contrast, neoadjuvant hormonal therapy prior to prostatectomy did not improve recurrence-free and overall survival, although there was a significant reduction in the positive surgical margin rates and a significant improvement in other pathological variables such as lymph node involvement, pathological staging and organ confined rates. However, the use of neoadjuvant hormones for a longer time, either 6 or 8 months prior to prostatectomy, was associated with a further reduction in positive surgical margins, and might improve the treatment outcome of the patients. More research is needed to guide patient selection, choice, duration and schedule of hormonal therapy prior to radiation therapy or surgery. A large Phase III study of neoadjuvant chemotherapy using docetaxel before prostatectomy is ongoing, and the results of this study are much awaited.