Cataract is the most common ocular damage in systemic lupus erythematosus (SLE). We analyzed data from the Hopkins Lupus Cohort longitudinally to identify the factors that predict onset of cataract prior to 60 years of age. The Hopkins Lupus Cohort is a clinical cohort of patients with SLE seen quarterly. This analysis was based on the follow-up experience prior to age 60 of 2,109 SLE patients who had not had a cataract prior to cohort entry. Patients saw their ophthalmologist every 6 months. Cataract was defined by the SLICC/American College of Rheumatology Damage Index. The rate of incident cataract was calculated in subsets of the follow-up defined by patient characteristics and history. Multivariable logistic regression models were fit to identify predictors of cataract while controlling for potential confounding variables. The analysis was based on 11,887 persons-years of follow-up, with median follow-up time of 4.1 years per patient. The incidence of cataract was 13.2/1,000 persons-years. Adjusting for other predictors, a cumulative prednisone dose equivalent to 10 mg/day for 10 years was a strong predictor of cataract (RR = 2.9, P = 0.0010). Disease activity measured by SELENA-SLEDAI (P = 0.0004) and higher systolic blood pressure (P = 0.0003) were associated with cataract. Duration of SLE, diabetes mellitus, smoking, cholesterol, renal involvement, immunological profile and medication history other than prednisone were not associated with cataract. Cataract development in SLE patients is multifactorial with prednisone, systolic blood pressure and disease activity all playing a role.