While periodontitis deteriorates patients’ quality of life, non-surgical periodontal treatment seems to offer an improvement. The purpose of the present study was to evaluate the impact of non-surgical and surgical periodontal treatment on the oral health-related quality of life (OHRQoL) utilizing patient-centered assessments and surrogate clinical measurements in Greek adults. Eighty-three individuals with chronic periodontitis were enrolled in the study. Assessment of OHRQoL with the use of the Oral Health Impact Profile (OHIP-14) questionnaire in conjunction with clinical measurements of pocket probing depth (PPD), plaque index (PI) and bleeding on probing (BOP) were performed at baseline (t0), after non-surgical therapy (t1) and after periodontal surgery (t2). A statistically significant reduction of OHIP-14 score was recorded at t1 and t2 examination compared to baseline (p < 0.001) and a statistically significant improvement in all clinical parameter at all time points was recorded (p < 0.05). No correlation between the clinical parameters and the total score of OHIP-14 was recorded at any time point. Non-surgical periodontal treatment seemed to improve OHRQoL in terms of OHIP-14 scores, whilst supplementary surgical periodontal therapy did not offer any additional benefit. No correlation was found between patients’ perception of quality of life expressed by OHIP-14 score and the surrogate clinical parameters.