Purpose: To evaluate the association of oral health-related quality of life (OHRQoL) with periodontal parameters and treatment needs in a Turkish population and compare the OHRQoL of patients with gingivitis and periodontitis. Materials and Methods: The present study had a cross-sectional design. The study population consisted of 404 patients with periodontitis (n = 130), gingivitis (n = 141) or periodontal health (n = 133). Patients' sociodemographic information as well as periodontal parameters such as plaque index (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL) and the community periodontal index of treatment needs were recorded. The impact of oral health on the patients' quality of life was assessed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Results: The OHIP-14 scores in subjects with gingivitis and periodontitis were higher than in periodontally healthy individuals (p 0.05). Although the total OHIP-14 scores in subjects with periodontitis were higher than those for the subjects with gingivitis, no statistically significant difference existed between the gingivitis and periodontitis groups (p > 0.05). When characterised according to periodontal treatment needs (TN), the total and individual domain OHIP-14 scores were highest in subjects at the TN3 level. The total OHIP-14 scores of subjects correlated with periodontal status, BOP, PD ≥ 4 mm (% of sites), CAL ≥ 4 mm (% of sites) and TN. Conclusions: Our results disclosed that the adverse effects on OHRQoL perceived by patients were similar in subjects with gingivitis and periodontitis. When planning treatment, it should be kept in mind that the pain and physical discomfort domains of the individual subscales are of primary importance to the patients. However, longitudinal studies are needed to clarify the relationship between periodontal status and OHRQoL. Keywords: gingivitis, oral health-related quality of life, periodontitis, periodontal treatment needs