Background and objectives: We aimed to find predictors for development of anemia in a large cohort of adults. Patients and methods: Cohort study of a large health database from a screening center at the Rabin Medical Center in Israel, between the years 2000-2013. We asked which variables, known at the first visit, would predict anemia at the last visit. Multivariable analysis was conducted using stepwise logistic regression analysis. Odds ratios (ORs) for anemia with 95% confidence intervals (CIs) were calculated. Results: Our cohort included 10,577 people. At baseline 4.4% were diagnosed with anemia and excluded. Therefore, 10,093 subjects, with a mean age of 42.3 ± 9 years comprised our study sample. At the end of follow-up of 4.7 ± 3.1 years, 307 developed anemia (3%). In men, independent predictors for development of anemia were diabetes mellitus (OR 3.00, 95% CI 1.41-6.39), age (OR 1.03, 95% CI 1.03-1.05, for 1 year increment), low MCV (OR 0.92, 95% CI 0.89-0.96, for every 1 fL unit increment) and elevated platelet count (OR 1.004, 95% CI 1.00-1.01 for 1000/μL unit increment). For women, high total serum protein level was a strong predictor for anemia (OR 3.44, 95% CI 2.33-5.08 for 1 mg/dL increment) as well as low triglycerides (OR 0.996, 95% CI 0.993-1.000 for 1 mg/dL increment). Conclusions: Subgroups who are prone to develop anemia include men with diabetes, and women with an elevated serum protein level and low triglycerides.