Objective: The aim was to assess the peri-implant clinical and radiographic parameters and whole salivary levels of interleukin (IL)-1β and IL-6 among type 2 diabetic and nondiabetic patients with and without peri-implantitis. Material and Methods: Ninety-one implants were placed in patients without type 2 diabetes mellitus (39 patients with and 52 patients without peri-implantitis; group 1). Eighty implants were placed in patients with diabetes (35 patients with and 45 patients without peri-implantitis; group 2). Peri-implant plaque index, bleeding on probing, probing depth, and marginal bone loss were measured. Unstimulated whole saliva samples were collected and IL-1β and IL-6 levels were measured using standard techniques. p < 0.05 was considered statistically significant. Results: In group 1, plaque index (p < 0.001), bleeding on probing (p < 0.001), probing depth (p < 0.001), and whole salivary IL-1β (p < 0.001) and IL-6 (p < 0.001) levels were significantly higher in patients with peri-implantitis than in those without peri-implantitis. Plaque index, bleeding on probing, probing depth, and marginal bone loss were comparable among all of the patients in group 2. Among patients with peri-implantitis, plaque index (p < 0.001), bleeding on probing (p < 0.001), probing depth (p < 0.001), marginal bone loss (p < 0.001), and whole salivary IL-1β (p < 0.001) and IL-6 (p < 0.001) levels were significantly higher in those with diabetes than in those without diabetes. Conclusion: Among individuals without diabetes, peri-implant plaque index, bleeding on probing, probing depth, marginal bone loss, and whole salivary IL-1 β and IL-6 levels were higher among patients with peri-implantitis compared to patients without peri-implantitis. Among patients with diabetes, the severity of the measured parameters appears to be influenced by the glycemic status rather than by peri-implantitis.