Abstract Purpose: Delivering linguistically competent care is critical to serving limited English proficiency patients, and represents a key national strategy to reduce health disparities. Current acceptable standards of communication with non-English speaking patients include providers communicating through professional interpretive services, or bilingual providers speaking patients’ non-English languages directly. This study tests the impact of patient-provider language concordance on patient satisfaction through the conduct of a randomized clinical trial. Methods and Materials: Eighty-three adult Spanish-speaking cancer patients were randomized to receive care from either 1) a bilingual physician speaking to a patient directly in Spanish or 2) from the same physician speaking English and using a professional interpreter service. Validated questionnaires were administered to assess patient-reported satisfaction with both provider communication and overall care. Audio recordings of initial consultations with oncologists were transcribed and analyzed for content variations. Results: Compared to using professional interpretive services, patients cared for in direct Spanish reported significantly improved general satisfaction, technical quality of care, care team interpersonal manner, communication, and time spent with patient. Specific to physician communication, patients rated direct Spanish care more highly in perceived opportunity to disclose concerns, physician empathy, confidence in physician abilities, and general satisfaction with their physician. Analyzing the content of consultation encounters revealed differences between study arms, with the direct Spanish arm having more physician speech related to patient history verification and partnering activities. Additionally, patients in the direct-Spanish arm were more likely to initiate unprompted speech, and ask their providers questions. Conclusions: This study demonstrates improved patient-reported satisfaction among Spanish-speaking cancer patients cared for in direct Spanish compared to patients cared for with interpreter-based communication. Further research into interventions to mitigate this patient-provider language barrier is necessary to optimize care for this minority population. Citation Format: Daniel M Seible, Souma Kundu, Alexa Azuara, Daniel Cherry, Steven Arias, Vinit Nalawade, Jonathan Cruz, Rolando Arreola, Elena M Martinez, Jesse Nodora, Douglas A Rahn, James D Murphy. The influence of patient-provider language concordance in cancer care: Results of the Hispanic Outcomes by Language Approach (HOLA) randomized trial [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A035.