Background: The aim of this study was to evaluate the effect of Photobiomodulation (PBM) as an adjunct to scaling and root planning (SRP) on salivary interleukin -1ß levels in Generalized Stage II Grade B periodontitis patient. Methods: All 45 systemically healthy patients who were included in the study initially received SRP. The PBM group (n= 25) received diode laser therapy as an adjunct to SRP. A diode laser with a wavelength of 940nm was used for PBM. Energy density of 12J/cm2 was applied at the orifice of the gingival margin from distance of 1 cm using as a continuous wave with setting 1.5 W for period of 5–10s of exposure for anterior teeth and premolars and 20s of exposure for posterior teeth. Saliva samples were collected from all patients and clinical parameters were recorded on baseline and 21 days after treatment. Interleukin- 1β levels in the collected saliva were measured.