Objectives To assess the association between chronic physical conditions and multimorbidity and mild cognitive impairment (MCI) in low‐ and middle‐income countries (LMICs). Design Nationally representative, cross‐sectional, community‐based study. Setting Six countries that participated in the World Health Organization Study on Global Ageing and Adult Health. Participants Individuals aged 50 and older (N=32,715; mean age 62.1 ± 15.6; 51.7% female). Measurements The definition of MCI was based on the recommendations of the National Institute on Ageing and Alzheimer's Association. Ten chronic conditions were assessed (angina pectoris, arthritis, asthma, cataract, chronic lung disease, diabetes mellitus, edentulism, hearing problems, hypertension, stroke). Multivariable logistic regression analysis was conducted to assess the association between chronic physical conditions, multimorbidity (≥2 chronic conditions), and MCI. Results The prevalence of multimorbidity was 49.8% (95% confidence interval (CI)=48.1–51.5%) and of MCI was 15.3% (95% CI=14.4–16.3%). After adjustment for potential confounders, edentulism (odds ratio (OR)=1.24), arthritis (OR=1.24), chronic lung disease (OR=1.29), cataract (OR=1.33), stroke (OR=1.94), hearing problems (OR=2.27), and multimorbidity (OR=1.40) were significantly associated with MCI. There was a gradual increase in the likelihood of MCI (1 condition: OR=1.21, 95% CI=1.03–1.42; ≥4 conditions: OR=2.07, 95% CI=1.70–2.52). Conclusion These results highlight the need to investigate the underlying mechanisms linking chronic conditions and MCI and whether prevention or treatment of chronic conditions or multimorbidity can reduce the onset of cognitive decline and subsequent dementia, especially in LMICs.