Health numeracy is associated with increased understanding of cancer risk reduction information and improved control of chronic disease. A cross-sectional survey was conducted among a primary care population to evaluate the effect of health numeracy on breast, cervical, and colorectal cancer screening. No association was found between health numeracy and cancer screening. However, at a baseline screening rate of 85%, increased knowledge (RR 1.06, 95% CI 1.02-1.08) and decreased perceived barriers (RR 0.93, 95% CI 0.92-0.95) were associated with increased screening rates. In conclusion, health numeracy was not predictive of cancer screening among a primary care population.