In this cross‐sectional analysis, we examined the relationship between soy and cruciferous vegetable intake and common endocrine therapy side effects among breast cancer patients.Participants were 193 non‐Hispanic white and 207 Chinese women (mean age=57.0) with stage 0‐III breast cancer and at least one year post diagnosis. Vegetables and soy foods intake was obtained from a food frequency questionnaire. Treatment side effects symptoms were assessed by a telephone interview. Self reported counts of side effect symptoms were categorized into “yes/no”. Dietary intake was categorized into 3 categories and odds ratios for adverse effects were computed adjusting for multiple confounders.48% of the women were postmenopausal and mean BMI=24.2. Most were inactive or minimally active. After multivariable adjustment, higher soy foods and isoflavones intake was associated with a lower odds of experiencing side effects of endocrine therapy such as hot flashes and vaginal dryness. Comparing highest to no intake of intake the OR for soy foods was 0.48 (95% CI=0.25, 0.93), and OR for isoflavones was 0.47 (95% CI=0.24, 0.91). Among Chinese women, higher isoflavones intake was associated with less self‐reported memory loss, OR=0.44 (95% CI=0.20, 0.99) and hair thinning 0.41 (95% CI=0.18, 0.93).Higher intake of soy foods or isoflavones is associated with a lower odds of endocrine treatment side effects among breast cancer survivors.