Worry about breast cancer risk has been found to be a barrier to mammography use by women with a family history of breast cancer in some studies, although worry is generally found to increase mammography use among average risk women. Our study sought to examine the association of worry with mammography use in a population-based sample of women stratified by family history associated risk for breast cancer. A population-based sample of 6512 women completed a telephone interview. Fourteen percent (n = 948) of these reported a family history suggestive of elevated risk, including at least one affected first-degree relative. To examine the effects of worry on mammography use in women, a logistic regression model, including family history associated risk, age, and worry, was tested. Although family history was a significant predictor of mammography use in bivariate examinations, in the multivariate model it was not significant after adjustment for age and worry, which remained statistically significant predictors of mammography (P < 0.05). The association between worry and mammography use was best described by a quadratic term. Interaction terms for family history-associated risk and worry were not statistically significant predictors of mammography use. Worry about breast cancer risk appears to be associated with mammography use in an inverted u-shaped pattern. Women reporting moderate levels of worry were more likely to use mammography annually than those who were either mildly or severely worried. Severe worry may be a barrier to mammography use for all women not only those with a family history.