Abstract Tobacco use is causally associated with 18 cancers and is a leading cause of preventable death. Individuals experiencing mental illness use tobacco at an elevated rate and consequently suffer from greater cancer-related morbidity and mortality. Unfortunately, local mental health authorities (LMHAs), a common setting to receive mental health services, do not prioritize tobacco dependence treatment despite robust evidence that tobacco cessation can enhance mental health in addition to reducing cancer incidence. Beliefs (Health Belief Model) and competence (Self Determination Theory) both play an integral role in shaping behavior. Consequently, this study examined employee and provider tobacco-related beliefs and competence in LMHAs to contextualize their tobacco intervention practices. The frequency of beliefs and competence related to provision of evidence-based tobacco cessation care was collected by e-survey from organizational representatives of 30 of the 39 LMHAs in Texas in 2021. Queries included if respondents agreed that patients should concurrently quit drugs/alcohol and tobacco (N=30 employees) and if they believed patients want to quit cigarette and non-cigarette (i.e., other) tobacco products (n=16 direct service providers). Providers were also asked if they thought that they had the competence to help patients quit smoking and other tobacco use, if they could tailor cessation treatment to patient needs, and about their intervention practices. Only 40% of LMHA representatives endorsed that patients should quit tobacco at the same time as other drugs. Furthermore, only 50% of providers believed that patients want to quit smoking and other tobacco use, respectively. About 70% of providers believed that they have the skills to help patients quit smoking and other tobacco use, respectively, but only 56% reported that they can tailor treatment. Finally, only 56% and 38% of providers recommend that patients stop smoking or other tobacco use, respectively, with 25% recommending smokers switch to vapes or smokeless tobacco products. Contrary to LMHA employee and provider beliefs, research indicates that most patients want to quit tobacco use and that concurrent tobacco use treatment can enhance patient sobriety for non-nicotine substance use disorders. Results demonstrate high levels of misinformation on concurrent tobacco and substance use treatment in LMHAs, which can subvert the provision of evidence-based cessation care. Educational interventions are needed to shift these beliefs, increase competence, and increase tobacco use intervention provision. This will not only help to address cancer disparities among patients but also improve mental health- a critical goal of LMHAs. Future research should investigate how to target tobacco-related beliefs, competence, and intervention behavior in LMHAs to broaden the reach of cancer prevention strategies. Citation Format: Ammar D. Siddiqi, Maggie Britton, Tzuan A. Chen, Isabel Martinez Leal, Anastasia Rogova, Midhat Z. Jafry, Bryce Kyburz, Teresa Williams, Lorraine R. Reitzel. Evaluating beliefs and perceived competence about tobacco cancer prevention practices in Texas local mental health authorities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2152.