Forty-two patients with chronic nonbacterial prostatitis (CNP) and twelve men without any urological complaints or history underwent intraprostatic tissue pressure measurement with a Stryker intracompartmental pressure monitor device. The pressures were measured under spinal anesthesia in connection with various surgical procedures. Tissue pressure was monitored at 10, 60 and 120 s after an injection of 1 ml saline. Significantly (P < 0.001) higher intraprostatic pressure values were registered at all the three time points in the patients with CNP compared to the controls. Our study shows that patients with CNP have elevated intraprostatic tissue pressures, probably reflecting increased tissue resistance and a poor tissue microcirculation status. It seems that this method can be used as a diagnostic tool to differentiate between various causes of chronic pelvic pain in the male. The aim is to develop further this method so that it is also suitable for outpatient use.