Interstitial laser coagulation (ILC) treatment is a recent technique in the treatment of BPH that is evolving rapidly. The results of a prospective randomised study vs transurethral resection of the prostate (TURP) is presented as well as results of patients treated with a temperature sensing laser system. The first study included 44 patients treated in a prospective randomised study (randomisation ILC vs TURP=2:1) comparing changes in objective and subjective parameters. In the second part of the study the outcome of the treatment of 34 patients with BPH using ILC performed with a temperature-sensing laser system are presented. The clinical outcome at 12, 26, 52 and 104 weeks was evaluated with symptom scores, quality of life measures, changes in voided volume, post void residual, and peak flow rate. In addition changes in prostate volume and urodynamic parameters at half a year follow-up are presented. In this randomised study patients improved markedly at any time during follow-up. In the ILC group there was a significant and persisting subjective improvement whereas the improvements in the TURP group were even more significant. The changes in voiding parameters, including changes in pressure-flow parameters, are superior in the TURP group compared to the changes in the ILC group. The retreatment rate for the ILC group is 21% compared to 7% in the TURP group, no patient with incontinence was documented in either group, while only one patients in the TURP group developed a urethral stricture. In the second part of the study, the clinical improvements following laser therapy using the temperature sensing treatment mode were more pronounced in voiding parameters when compared to those of the randomised laser group. Lower energy interstitial laser treatment of the prostate results in a significant improvement of all clinical parameters that are inferior to improvement following transurethral resection of the prostate. When using a temperature sensing system, the objective results of laser treatment improved and seem to be more durable.