Knee pain is a condition recognized for its high functional impact in the older population. Knowledge about the characteristics of these demands in Primary Health Care (PHC) is scarce, which makes it difficult to plan lines of care aimed at pain management in this population. The objective of this study was to investigate characteristics of knee pain among older adults users of primary health care, according to sociodemographic aspects. A cross-sectional study was carried out with 201 older adults in three randomly selected health units. Knee pain was classified as chronic (>3 months) and acute (<3 months). The Analog Pain Scale was applied to assess the intensity, scored from 0 to 10, and questions about the impact of pain on daily life and demand for health services. Gender, age, presence of a partner, and education were recorded. Chronic knee pain was reported by 39.8% of participants; 24.9% reported functional impact and 23.9% sought a health service. Presence of pain (p=0.021) and functional impact (p=0.016) were more frequent among those who did not have a partner and the search for health services was more frequent among those with higher education. Acute knee pain was reported by 37.8% of participants, mean pain intensity was 2.4 (SD:3.6), and was associated with higher education and not having a partner. The demand for care for older adults with knee pain in PHC is high and is characterized as being functionally impactful and stimulating the demand for health services, in addition to being unequal in terms of education and the presence of a partner.