Background: Anxiety is a common mental disorder among older people who live in the Western world, yet little is known about its prevalence in low- and middle-income countries. Aims: We investigated the prevalence of anxiety and its correlates among older adults in low- and middle-income countries with diverse cultures. Method: Cross-sectional surveys of all residents aged 65 or over (n = 15 021) in 11 catchment sites in 7 countries (China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru) were carried out as part of the 10/66 collaboration. Anxiety was measured by using the Geriatric Mental State Examination (GMS) and the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT) diagnostic algorithm. Results: The age- and gender-standardised prevalence of anxiety varied greatly across sites, ranging from 0.1% (95% CI 0.0-0.3) in rural China to 9.6% (95% CI 6.2-13.1) in urban Peru. Urban centres had higher estimates of anxiety than their rural counterparts with adjusted (age, gender and site) odds ratios of 2.9 (95% CI 1.7-5.3). Age, gender, socioeconomic status and comorbid physical illnesses were all associated with a GMS/AGECAT diagnosis of anxiety, and so was disability (World Health Organization Disability Assessment Schedule II). Conclusions: Anxiety is common in Latin America. Estimates from this region are similar to the ones from high-income European countries found in the literature. As demographic change will occur more rapidly in these countries, further research exploring the mental health of older people in developing areas is vital, with the inclusion of other specific anxiety disorders, along with evidence for strategies for supporting those with these disorders.