Chronic pain is currently considered a public health problem with high costs to the individual and society. To improve prevention and treatment of chronic pain, epidemiologic studies are mandatory for assessing chronic pain. The aims of this study were to estimate the prevalence of chronic pain in the adult Danish population and to analyze associated factors such as diseases, immigration, and opioid use. This cross-sectional survey combines individual-based information from the Danish Health Survey (2010) and official Danish health and socioeconomic, individual-based registers. The simple random sample consisted of 25,000 individuals (≥16 years old) living in Denmark. In all, 60.7% completed a mailed or online questionnaire. Associations were examined with multiple logistic regression analysis. The study population consisted of 14,925 individuals in whom a high prevalence of chronic pain (26.8%, 95% confidence interval: 26.1 to 27.5) and a high prevalence of opioid consumption (4.5%) were observed. Other aspects of particular note: (1) a higher prevalence of chronic pain occurred among individuals with cardiovascular and chronic pulmonary diseases than among individuals with cancer; and (2) individuals with a non-Western background reported a higher pain prevalence, higher pain intensities, and more widespread pain than individuals with Danish background; however, opioids were more frequently used by native Danes. The prevalence of chronic pain as well as opioid use in Denmark are alarmingly high, and the relevance of opioid consumption is unknown.