Purpose: Corticosteroids are known to cause cataracts, but the effects of other medications on the lens are unclear, The aim of this study was to investigate the relationships between cataracts and a range of medications, including alfopurinol, aspirin, chloroquine, diuretics, phenothiazines, and simvastatin. Design: Population-based cross-sectional study. Participants: 3654 individuals 49 to 97 years of age (response rate, 82%) from an urban community near Sydney, Australia, were included. Testing: Lens photography. Primary Outcome Measure: Lens photographs were graded for the presence and severity of cortical, nuclear, and posterior subcapsular cataract. Results: After adjusting for numerous potential confounders in ordinal regression models, use of phenothiazines was associated with nuclear cataract (adjusted odds ratio [OR], 2.18; 95% confidence interval [CI], 1.01-4.74); long-term aspirin users (greater than or equal to 10 years) had higher prevalence of posterior subcapsular cataract than did nonusers and short-term users (test for trend, P = 0.02); and the antimalarial drug mepacrine was associated with posterior subcapsular cataract (adjusted OR, 3.56; 95% CI, 1.56-8.13). There was a suggestion that use of chloroquine-like drugs for more than 1 year (test for trend, P = 0.12) might also be associated with posterior subcapsular cataract, Antihypertensive medications, cholesterol-lowering drugs, and allopurinol were not associated with any type of cataract. Potassium-sparing diuretics were the only diuretic to show any evidence of an association with cataract (test for trend for posterior subcapsular cataract, P = 0.14). Amiodarone was associated with cortical cataract (age- and gender-adjusted OR, 3.84; 95% CI, 1.01-14.81), but there were too few users to do analyses adjusted for multiple confounders. Conclusions: Most drugs commonly used in the community do not appear to be associated with cataract. The findings of this study do not support the hypothesis that aspirin protects against cataract.