Laser transurethral resection of the prostate (TURP) is becoming widely used for surgical management of lower urinary tract symptoms from benign prostatic hyperplasia. Yet, one drawback to laser vaporization is the lack of a prostatic tissue sample for pathologic evaluation. We report the case of a 57-year-old man who presented with urinary obstruction, a normal digital rectal examination and a prostate-specific antigen level of 0.44 ng/mL. The patient then underwent transrectal ultrasonography to determine the size of his prostate (60 g). On the basis of these normal findings, laser TURP was performed. The patient's symptoms did not improve after the procedure, and cystoscopy confirmed continued prostatic obstruction. The patient subsequently underwent bipolar TURP, and the pathologic examination of the prostate chips revealed highly aggressive prostate adenocarcinoma with neuroendocrine differentiation. We discuss the potential drawbacks of laser TURP in the diagnosis of clinically undetectable prostate cancer.