Objective/Hypothesis: This study was undertaken to determine the efficacy of a new treatment system with a high power diode laser and rigid nasal endoscopic device on patients with perennial allergic rhinitis at an outpatient clinic. Study Design: A pilot study involving 30 patients with perennial allergic rhinitis refractory to conventional treatment was performed. Method: A high power diode laser and rigid nasal endoscopic device were used. The high power diode laser with an 805 nm-wavelength has been applied for laser surgery. The entire surface of the inferior turbinate until the posterior part was treated by a high power diode laser beam. To assist the laser surgery of the inferior turbinate, a specially designed nasal endoscope (Baerenbach nasalendoscope, Nisco), xenon light sources, and television monitors were used. The 4-mm 0° telescope which measured with 7 cm length was equipped with an infused cannula and hand grip in order to remove any smoke while performing the procedure. Results: 11 patients (36.7%) and 6 patients (20%) out of 30 patients obtained either excellent or good results at 1 month after laser surgery, respectively. Thereafter, the improvement rate increased to 43.3 with excellent and 23.3% with good results at 3 months, respectively. Conclusion: These findings suggest that a high power diode laser with a nasal rigid endoscopic device can be successfully utilized for the surgical treatment of perennial allergic rhinitis on an outpatient clinic.