Objective: Sexual minority women are at heightened risk for breast and cervical cancer and are less likely than heterosexual women to obtain timely screenings for breast and cervical cancer. This study tested hypotheses about potential factors that contribute to nonadherence to these screenings among sexual minority women. Method: Sexual minority women living in the United States aged 18 to 74 who met other eligibility criteria (n ϭ 1,115) were recruited to complete an online questionnaire. Screening utilization, demographic information, sexual orientation, and health care indicators were collected. Variables linked to minority stress were assessed: stigma consciousness, internalized homophobia, rejection sensitivity, fear of negative evaluation, and concealment of sexual orientation from one's health care provider. Logistic regression models tested whether these psychological variables were independently associated with nonadherence for Papanicolaou (Pap) test and breast cancer screening. Results: The variable of concealment had the strongest positive independent association with failure to obtain timely Pap tests. Among women who had a general physical in the last year, concealment, stigma consciousness, rejection sensitivity, and fear of negative evaluation were all positively associated with lower rates of timely Pap tests. Among all women, these psychological variables were positively associated with never obtaining a Pap test and concealment was also negatively associated with clinical breast exam adherence. Conclusions: Psychological barriers and concealment of sexual identity may hinder adherence to screening guidelines among some sexual minority women. Strategies facilitating positive experiences of disclosure to health care providers and addressing psychological factors related to minority stress could promote adherence.