Objectives: In this paper we propose a new Global Oral Health Scale that will allow the infectious potential of the oral cavity, clinically manifest as local and focal infections, to be condensed into a single parameter. Study Design: Based on a number of oral health scales previously designed by our group, we designed a final version that incorporates dental and periodontal variables (some of them evaluated using corroborated objective indices) that reflect the presence of caries and periodontal disease. Results: The application of the proposed oral health scale requires the examination of 6 sites per tooth (mesio- buccal, medio-buccal, disto-buccal, disto-lingual, medio-lingual and mesio-lingual). The following variables are analysed: number of tooth surfaces with supragingival plaque, determined using the O'Leary index; number of teeth with caries and the severity of the caries; number of tooth surfaces with gingival inflammation, determined using the Ainamo and Bay index; and number of tooth surfaces with pockets >=4 mm and severity of the pockets. These variables are then grouped into 2 categories, dental and periodontal. The final grades of dental and peri - odontal health correspond to the grades assigned to a least 2 of the 3 variables analysed in each of these categories. The category (dental or periodontal) with the highest grade is the one that determines the grade of the Global Oral Health Scale. Conclusion: This scale could be particularly useful for the epidemiological studies comparing different populations and for analysis of the influence of distinct degrees of oral health on the development of certain systemic diseases.