Background. Most physicians use digital rectal examination (DRE) to help detect prostate cancer and to estimate the prostates' size. The accuracy of DRE is known to be limited. We evaluate the ability of doctors to palpate the whole prostate with DRE. Methods. At time of transrectal ultrasound (TRUS) the distances from the anus to the apex and base of prostates were measured. The TRUS's distances were compared to the mean index finger length of our clinic doctors. Results. The ability of the urologist to reach and examine the apex, half, three quarters and the whole prostate was in 93.7%, 66.3%, 23.2% and 3.2% of cases respectively. Conclusions. In most cases it was impossible to palpate the whole prostate. Anatomical location and volume of the examined prostate, as well as the length of his own index finger limit DRE and allow the examination of only a small portion of the prostate.