Objectives: 1) To describe physical activity in the Spanish adult working population aged 1670 years in 2009, and 2) to describe the prevalence of physical activity according to sociodemographic features, self-perceived health status, co-morbidity, and lifestyle habits. Design: An epidemiological population based descriptive study was conducted using individual data taken from the European Health Survey for Spain. Setting: Community. Participants: The number of subjects aged 16-70 years included in the study was 10,928 (5,628 women and 5,300 men). Interventions: None. Main variables: Physical activity and intensity were assessed from questions included in the interview-survey. An analysis was performed on the socio-demographic characteristics and self-rated physical and mental health, using multivariate logistic regression models. Results: Not having a partner (OR 1.44; P < .001), have university studies (OR 1.62; P < .001), nOn-smoker (OR 1.50; P < .001), and taking medications (OR 1.22; P < .5) were a predictor of intense physical activity in men. The first 3 factors are equal for intense activity in women. In contrast, obesity (OR 0.58; P < .001), and 36-50 years (OR 0.68; P < .001) were factors related to low activity in men. Aged between 36-50 years (OR 1.26; P < .01), suffering >= 2 co-morbid conditions (OR 1.30; P < .001), and non-smoker (OR 1.17; P < .5) were also associated with higher probability of reporting moderate physical activity in women. The positive mental health was significant for physical activity in both sexes (OR 1.01; P < .5). Conclusions: This study identified several factors that appear to influence physical activity in the Spanish adult working population, with potential implications for healthcare providers. (C) 2014 Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).