Periodontal disease or periodontitis is an inflammatory disease with a hight prevalence. According to the last oral health survey of the Spanish population, between 24% and 37% of Spaniards aged over 35 years have periodontitis and 6% to 10% of the adult population have deep periodontal pockets. The aim of this study was to determine the association between risk factors and the presence of periodontal pockets in the adult population. A cross sectional or prevalence study of a representative sample of the adult population of the Valencia region was designed. The sample was recruited at 35 health centres, The study was conducted in November and December 2006 under standardized conditions as regards light sources, equipment and instruments and the position of the three previously calibrated dentist examiners. The sample examined consisted of 733 individuals (220 men and 513 women). Measured by the CPI, 13% were healthy and 5.5% presented bleeding. The prevalence of calculus was 59.3%, that of 3.5-5.5 mm pockets was 15.8% and that of pockets deeper than 5.5 mm was 4.6%. Almost half the sextants were healthy (2.89), 0.61 presented bleeding and 1.74 presented calculus. The mean number of sextants affected by 3.5-5.5 mm pockets was 0.46 and 0.07 presented deep pockets (>5.5 mm). An adjusted multiple logistic regression model with the presence of periodontal pockets as the dependent variable showed that the significant independent variables were low social class (OR=1.81), smoking (OR=1.68), primary education (OR=1.57), male gender (OR=1.56) and age (OR=1.08). The other study variables were not significant in this model. Socioeconomic factors such as primary education and low social class, as well as gender, age and smoking, were found to be associated to a significant degree with greater prevalence of periodontal disease in the adult population.