This is the first study to report the prevalence of general obesity and abdominal obesity (AO) in the adult population of Spain based on measurements of weight, height and waist circumference. The data are taken from the ENRICA study, a cross-sectional study carried out between June 2008 and October 2010 in 12,883 individuals representative of the non-institutionalized population on Spain aged 18 years and older. Anthropometry was performed under standardized conditions in the households by trained interviewers. Overweight was considered as body mass index (BMI) 25–29.9 kg m−2, and obesity as BMI ≥ 30 kg m−2. AO was defined as waist circumference >102 cm in men and >88 cm in women. The prevalence of obesity was 22.9% (24.4% in men and 21.4% in women). About 36% of adults had AO (32% of men and 39% of women). The frequency of obesity and of AO increased with age and affected, respectively, 35 and 62% of persons aged 65 and over. The frequency of obesity and AO decreased with increasing educational level. For example, 29% of women with primary education or less had obesity vs. only 11% of those with university studies. The prevalence of obesity was very high in the Canary Islands and in the south of Spain.