Objective: The purpose of this study was to determine the effect of light-emitting diode photomodulation (LED PBM) on implant osseointegration by measuring implant stability changes by resonance frequency analysis (RFA) and measuring interleukin-1 beta (IL-1 beta), transforming growth factor-beta (TGF-beta), prostaglandin-E-2 (PGE(2)), and nitric oxide (NO) levels in peri-implant crevicular fluid (PICF). Background data: Light therapy modulates various biological events and allows improved wound healing in ischemic and wounded tissues. Methods: Fifteen patients (8 control, 7 LED) participated in the study. In the LED group, LED device at a wavelength of 626 nm in the near-infrared (NIR) region (treatment array area: 4.80 cm(2); average intensity: 38.5 mW/cm(2); total power: 185 mW; total energy: 222 J; average density: 46.2 J/cm(2)) was applied for 20 min over the surgical area during 3 weeks, three times in a week, starting from the operation day. Implant stability quotient (ISQ) values were recorded at the time of operation, and 2, 4, 8, and 12 weeks postoperatively. PICF samples were collected in postoperative weeks 4 and 12 and IL-1 beta, TGF-beta, PGE(2), and NO levels were evaluated. Clinical indices were recorded around implants in postoperative weeks 4 and 12. Results: In the control group, significant reduction of ISQ values from week 2 to week 12 were demonstrated. In the LED group, baseline ISQ values were maintained during the study and no significant changes were observed. Changes in biochemical parameters were found to be similar between groups over time. However, in the LED group, a negative correlation was found between PGE(2) and ISQ values. Conclusions: LED application to surgical area has a positive effect on the osseointegration process, and implant stability can be maintained.