The capacity of dental clinicians and researchers to assess oral health and to advocate for dental care has been hampered by limitations in measurements of the levels of dysfunction, discomfort and disability associated with oral disorders. The purpose of this research was to develop and test the Oral Health Impact Profile (OHIP), a scaled index of the social impact of oral disorders which draws on a theoretical hierarchy of oral health outcomes. Forty nine unique statements describing the consequences of oral disorders were initially derived from 535 statements obtained in interviews with 64 dental patients. The relative importance of statements within each of seven conceptual subscales was assessed by 328 persons using Thurstone's method of paired comparisons. The consistency of their judgements was confirmed (Kendall's mu, P < 0.05). The reliability of the instrument was evaluated in a cohort of 122 persons aged 60 years and over. Internal reliability of six subscales was high (Cronbach's alpha, 0.70-0.83) and test-retest reliability (intraclass correlation coefficient, 0.42-0.77) demonstrated stability. Validity was examined using longitudinal data from the 60 years and over cohort where the OHIP's capacity to detect previously observed associations with perceived need for a dental visit (ANOVA, p < 0.05 in five subscales) provided evidence of its construct validity. The Oral Health Impact Profile offers a reliable and valid instrument for detailed measurement of the social impact of oral disorders and has potential benefits for clinical decision-making and research.