Objective: To determine the effect of the severity of periodontitis on quality of life related to oral health.  Methods: Cross-sectional study that recruited a sample of 229 adults with mild, moderate and severe periodontitis. Quality of life was measured with the Oral Health Impact Profile (OHIP-14).  Results: Subjects with moderate periodontitis were found to have worse OHRQoL (40.2%) compared to those with mild (31.8%) and severe (28%) periodontitis. Statistically significant differences were found between the groups regarding functional limitation (p=0.004), physical pain (p=0.004), physical disability (p=0.015), psychological disability (p=0.01) and social disability (p= 0.004).  Conclusions: the psychological disability and psychological distress dimensions were similarly affected regardless of periodontal status. In subjects with severe periodontitis there was greater involvement in functional limitation and physical disability.