Objective: The aim of this study was to evaluate the prevalence and intensity of dental pain in children according to size of municipality, associated factors and absenteeism. Methods: The sample consisted of children aged 12 years old from public and private schools drawn from eight cities in the region of Campinas (SP). A questionnaire was applied to obtain dental pain, demographic, socioeconomic data, and a clinical examination was carried out to evaluate the experience of having a cavity. The outcome for the logistic regression analysis was having pain and the outcome for the negative log-binomial regression was the intensity of pain. The significance level was 5%. Results: The sample consisted of 1,233 children, and 16.7% reported pain in the last six months. Dental pain was the cause of 46.4% of school absenteeism during this period. The prevalence of pain was lower among households with high income (p=0.023) and higher among nonwhites (p=0.027). Pain intensity was lower in medium-sized cities (p=0.02) and small cities (p=0.004), and higher in children whose parents had a lower educational level (p=0.003), children who sought out a dentist for the pain (p=0.04) and who had untreated cavities (p=0.04).Conclusions: The prevalence and intensity of dental pain in children aged under 12 are related to socioeconomic aspects of the family, such as low-income and parents with a low level of education, which impact daily activities as seen through school absenteeism. Pain intensity was lower in medium and small cities. Oral health promotion strategies in this age group should be encouraged to avoid dental pain.