Purpose: Perceived risk has been shown to influence behavior. We hypothesized that personal belief in luck may be related to perceived risk and may also directly or indirectly influence behaviors. An unlucky person may feel that bad outcomes (e.g., surgical complications) are likelier to happen to him than the average person. We examine the relationship between women's belief in luck and their perceived risk of developing breast cancer in women with a first degree relative with breast cancer. Methods: Women with a family history of breast cancer were recruited from the community. Study participants completed the Belief in Luck survey, which has five subscales: personal good luck, personal bad luck, general belief in luck, belief in the luck of others, and the influence of luck on decision making. To measure perceived risk, women completed two questions rating what they thought the average woman's risk for breast cancer was and what they thought their risk for breast cancer was on a scale from 0-100%. Results: In this sample of 172 women, 78% thought that they had a higher risk of developing breast cancer than an average woman. There was a significant positive correlation between an individual's estimate of her risk of developing breast cancer and belief in personal bad luck (r= .17; p < .05) and a significant negative correlation between an individual's estimate of her probability of developing breast cancer and belief in personal good luck (r= -.17; p < .05). There was no significant relationship between belief in personal good luck and personal bad luck (r = .07; p = .34) meaning that believing you are lucky is different from believing you are not unlucky. Personal luck was unrelated to subjects' estimates of the average woman's percentage chance of developing breast cancer. Conclusions: Women who believe they are lucky may think that their risk of developing breast cancer is lower than women who believe they are unlucky. These beliefs do not appear to influence women's perceptions of others' risk of developing breast cancer. More generally, belief in personal luck may affect individuals' risk perceptions, which in turn may influence health decision making and behavior. Future investigations should work toward better explaining the relationship between belief in luck, risk perceptions, and health behaviors.