Medication Alasens is established to be capable of selectively accumulating in tumor cells and fluoresce in blue light of certain spectrum. The study was aimed at intraoperative analysis of photodynamic diagnosis possibilities in patients with prostate cancer for the evaluation of surgical margin status after radical prostatectomy. Study included 45 patients with local and locally advanced prostate cancer who underwent radical surgeries: laparoscopic extraperitoneoscopic prostatectomies in 15 (33%) patients and retropubic prostatectomies in 30 (67%) patients. After prostate, seminal vesicles were excised visual analysis of fluorescent effect in blue light was carried out in prostate, bladder neck and posterior urethra bed. Pathologic foci of red light were excised additionally and sent for histologic examination separately. After morphologic reports we carried out retrospective analysis of validity and falseness of the results of photodynamic diagnosis. Overall sensitivity amounted to 69%, specificity to 84%. Sensitivity of laparoscopic method accounted for 100%, specificity 90%. In group of patients operated on via open approach sensitivity was 55%, specificity 81%. Photodynamic diagnosis is an effective and safe method of surgical margin verification in radical prostatectomy. Further investigations are necessary to learn efficacy and work out technique of photodynamic diagnosis.