This study examined the use of the Pap cervical cancer screening test among women with mental disabilities in Taiwan and analyzed factors related thereto. Data were obtained from three national databases in Taiwan: the 2008 database of physically and mentally disabled persons from the Ministry of the Interior, 2007-2008 Pap smear test data from the Health Promotion Administration, and claims data from the National Health Insurance Research Database. The study subjects included 49,642 Taiwanese women aged ≥30 years with mental disabilities. Besides descriptive and bivariate analyses, logistic regression analysis was also performed to examine factors affecting Pap smear use. In 2007-2008, Taiwanese women with mental disabilities had a Pap screening rate of 11.05%. Age, income, education, marital status, catastrophic illness/injury, relevant chronic illnesses, and severity of disability were identified as factors affecting their Pap smear use. Age and severity of disability were negatively correlated with Pap screening, with the odds of screening being 0.37 times as high in ≥70-year-olds as in 30-39-year-olds and 0.49 times as high for very severe disability as for mild disability. Income was positively correlated with Pap screening. Being married (OR=2.55) or divorced or widowed (OR=2.40) relative to being unmarried, and having a catastrophic illness/injury (OR=1.13), cancer (OR=1.47), or diabetes (OR=1.25), were associated with greater odds of screening. In Taiwan, women with mental disabilities receive Pap smears at a far lower rate than women in general.