Abstract Background Many cancer survivors experience late effects from their cancer treatment including second cancers. Breast cancer risk in Hodgkin lymphoma (HL) survivors is estimated at 35% by age 50 years1 with a 40-fold increase when treated with chest radiation prior to age 20 years2. For patients who received chest radiation between ages 10 and 30 years, NCCN recommends annual screening mammogram and breast MRI 10 years after chest wall radiation or after age 30 and 25 years respectively3. We designed a web-based intervention to improve knowledge, intent to screen and uptake of breast cancer screening among long-term, high-risk HL survivors.Methods We invited 263 long-term HL survivors treated with chest radiation, of which 60 women were enrolled. Participants were randomized 1:1 to web-based intervention or control groups. The web-based intervention consisted of daily, interactive, highly tailored learning modules over the course of one week. Both groups received handouts on potential complications from cancer treatment and screening recommendations. All participants were invited to a baseline survey, first follow-up survey 1-2 weeks post intervention, and a final survey 3 months post intervention. In total, 53 participants completed the baseline survey, and to-date 41 the first follow-up survey. The last 3-month follow-up surveys are due in fall 2020. We compared frequencies of who correctly answered questions regarding potential complications from prior treatment and breast cancer screening recommendations at baseline vs. first follow-up in the intervention and control groups using Chi-squared and Fisher’s exact tests. P value < 0.05 was considered significant.Results At baseline, participants were on average 49 years old, and 22.4 years out from their HL diagnosis. Baseline self-reported adherence to annual mammography and breast MRI screening was low: 55% of all participants reported receiving annual mammograms, and only 6% reported annual MRIs. At baseline, 79% of participants reported awareness of complications from previous treatments however, only 27% correctly identified national guidelines on breast cancer screening for HL survivors who received chest radiation. At one week after the intervention, individuals assigned to the intervention (compared with controls) more often 1) reported knowing how to reduce the risk from prior treatments (89.5% vs. 50%, p = 0.009), 2) correctly identified national guidelines on screening (63.2% vs. 27.3%, p=0.007) at first follow-up. Our preliminary data did not show an increase in intent to screen or uptake of screening shortly after intervention. Conclusions Adherence to breast cancer screening recommendations is low among long-term, high-risk HL survivors. Preliminary analysis of an RCT comparing a web-based intervention to paper handouts identified improved knowledge regarding current national guidelines on breast cancer screening and how to reduce the risk of complications from prior HL treatments. Further research should address barriers to screening and interventions to address them.