Abstract Background: Despite national guidelines for routine screening mammography at least every two years beginning at age 40 for all women, and common knowledge of the increased risk associated with a family history, many women with a family history of breast cancer do not follow these recommendations. We sought to determine (a) the reasons why these women fail to adhere to screening guidelines, and (b) how these reasons compared with the general population in a nationally representative sample. Methods: The National Health Interview Survey (NHIS), conducted annually by the Centers for Disease Control, is designed to be representative of the US population. The 2010 NHIS Cancer Supplement was used to evaluate the most common reasons women with a first degree family history of breast cancer cited for not having a mammogram in the past two years. Results: In 2010, there were 9631 women over the age of 40 (representing 73,448,042 people in the population) surveyed. Of these, 12.5% had a first degree family history of breast cancer. Overall, 21.5% of women over 40 claimed they did not have a mammogram within the past 2 years, and this rate was not significantly different between those with a first degree family history of breast cancer and those without (20.5% vs. 21.6%, respectively, p = 0.452). The reasons why women with and without a family history failed to adhere to screening guidelines, however, significantly differed, primarily driven by the fact that women with a first degree family history of breast cancer who were older than age 40 knew that they were not too young to have a mammogram (see table below, p<0.001). Still, 27.9% of women with a first degree family history of breast cancer said they never thought about getting a mammogram, and 7.2% felt they didn't need one. Of note, more women with a family history of breast cancer claimed that their doctor said they didn't need a mammogram than those without a family history (13.8% vs. 12.2%). Conclusions: While women with a first degree family history of breast cancer are known to be at increased risk, they are not more likely to adhere to screening mammography guidelines than the general population and over 20% will not have had a mammogram within the past two years. Over a third of these women at increased risk report that they didn't think about it or didn't think they needed one, and 13.8% state their doctor didn't recommend a mammogram. These data highlight a significant need to better educate women with a family history of a first degree relative with breast cancer and their physicians regarding the need for appropriate screening. Proportion (%) First Degree Family HistoryNo First Degree Family HistoryNever thought about it27.8931.36Didn't need it7.159.32Doctor didn't say I needed it13.8212.17Haven't had any problems10.899.14Put it off12.4711.14Too expensive13.3412.36Too unpleasant3.173.36Too young01.96Don't have a doctor1.701.92Other9.577.28 Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-13-04.