Objectives: Ascertain the oral health status of the adult population in the Valencia region of Spain. Study design: A cross sectional prevalence study was conducted on a sample of 1264 adults, comprising 733 individuals aged 35-44 years and 531 individuals aged 65-74 years. Data collection was carried out in 2006. In both age groups (younger adults and older adults), the clinical examinations were carried out by calibrated dentists (Kappa >0.76). Results: The caries prevalence in the group of 35-44 year-old subjects was 92.2% (DMFT=7.64). In the group of 65-74 year-old subjects, it was 98.3% (DMFT=16.38). The F/DMFT percentage of the younger adults was 66% and that of the older adults was 16.3%. The edentate percentage was 0.1% in the group of 35-44 year-old subjects and 20.7% in the group of 65-74 year-old subjects. Calculus prevalence was almost 60% among the younger adults. Nearly 22% of the younger adults and 26% older adults presented periodontal pockets, although only a minority (4.6% and 4.3%) were CPI score 4. Significant differences in the various indices were found in relation to institutionalization and socio-economic status. Conclusions: The caries prevalence (DMFT>0) found in the two age groups studied remains very high: over 90%. The worst health status is found in certain groups, such as the institutionalized elderly and adults with a low socioeconomic status.