A prostate treatment system having a light delivery device positionable in a transurethral device for treatment of benign prostatic hyperplasia (BPH). The light delivery device includes light generator, such as light emitting diodes (LED), laser diodes (LDs) or a diffusion quartz fiber tip connected to a light generator or a light emitting polymer which produces light at a selected wavelength or waveband or alternative sources of suitable light energy. The treatment device may further include a temperature monitoring system for monitoring the temperature at the treatment site. A light-activated drug is administered to the treatment site prior to light activation. The light-activated drug therapy induces cell death of the target tissue. The device provides a minimally invasive transurethral method for treatment of BPH or prostate cancer.