Background: Peri-implantitis results after inflammation and bone resorption around implant site. The crevicular fluids present in that region are rich in N-Telopeptide (NTx) and Calprotectin, which are assumed as potential biomarkers. The aim was to assess and compare the calprotectin and NTx levels in the peri-implant sulcular fluid (PISF) from implant sites with or without peri-implantitis. Methodology: A total of fifty healthy patients with a single dental implant were recruited. The peri-implant clinical parameters, namely; probing pocket depth (PPD), bleeding upon probing (BOP), and gingival index (GI), was recorded for each patient. Radiographic images for each implant were obtained to assess the bone loss. PISF was collected using sterile paper strips for detection of calprotectin and NTx levels using the ELISA technique. The relationships between the peri-implant clinical parameters and the level of PISF calprotectin and NTx were analyzed. Results: The overall mean calprotectin level in PISF samples was 120.7 ± 0.78ng per µL and 235.4 ± 0.42ng per µL for healthy and diseased groups, and these values were statistically significant (p=0.003). The overall mean NTx level in PISF samples was 6.93 ± 0.52 ng per µL and 10.78 ± 0.33 ng per µL for healthy and diseased groups, respectively, and these values were statistically significant between the groups (p=0.002). The mean bone loss in healthy and disease sites was 48.8% and 20.2%, respectively. There was a positive correlation between GI scores and Calprotectin (r=0.57; p<0.001); PPD and Calprotectin (r=0.67; p<0.001). Similarly, a positive correlation was also observed between bone loss rate and NTx (r=0.61; p<0.001). Conclusion: The calprotectin and NTx levels in the PISF could be a promising biomarker for peri-implant inflammation and bone destruction in patients with peri-implantitis.