Abstract Background: Neoadjuvant therapy in breast cancer is considered standard treatment for the majority of patients with locally advanced breast cancer. Its use has been extended to early breast cancer aiming to downstage the extent of disease and surgery in the breast and/or axillary lymph nodes, to provide information regarding effectiveness of systemic therapy (which might guide adjuvant treatment recommendations), to provide prognostic information, as well as to extend time for appropriate genetic testing and planning breast reconstruction. However, little is known about patient decision making and preferences in this scenario. We aimed to describe patients’ preferences regarding neoadjuvant chemotherapy (NAC) for early breast cancer, patient decision-making patterns, and satisfaction with their decisions. Methods: Single arm prospective study at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City. We included patients aged ≥18 years with recent localized and operable breast cancer diagnosis. Electronic preferences and decision-making questionnaires were completed by each patient before NAC was started. A decision regret scale was completed within the first month after surgery was performed. Demographic and clinico-pathologic characteristics were extracted from the electronic medical records. Results: From March 2020 to April 2023, 29 women were enrolled. Mean age was 49.2 (SD 16.2), 55.5% (n=16) were married or had a partner, 79.3% (n= 23) had at least one child, 58.6% (n=17) had high school or higher education, and 48.2% (n=14) were housewives. 75.8% of women answered that they were proposed to be treated with NAC because of the tumor size, 55.1% due to positive lymph nodes, 72.4% to obtain a conserving surgery and 72.4% to obtain prognostic information. In 75.8% of the cases the oncologist made the decision of NAC and in 96.5% the chemotherapy schedule was explained to patients and their families. 82.7% of women answered that it was important for them to have a breast conserving surgery, 93.1% were worried about adverse events, 79.3% thought that there were possibilities to disappear the tumor with the chemotherapy and 31% thought that if the tumor disappear, they would not require surgery. After surgery was performed 96.1% answered that the decision of NAC was the right one, 7.6% would not make the same choice, and 23% felt that the decision to receive NAC caused them harm. Conclusion: Our study suggests that the reason to make a treatment decision related to NAC for early breast cancer was discussed and explained to the majority of the patients. However, physicians’ opinion was the most powerful to influence decision. A significant proportion of patients desire to have a conserving surgery and were worried about adverse events. Perspectives of patients’ preferences regarding NAC should be considered in treatment decision making to improve their decision satisfaction. Citation Format: Yanin Chavarri-Guerra, Haydee Cristina Verduzco-Aguirre, Roberto Gonzalez-Salazar, Ilana de la Puente Tawil, Paulina Quiroz-Friedman, Alejandro Alfaro-Goldaracena, Sofia Sanchez-Roman, Zuleyma Nieto-Garcia. Patient decision making and preferences regarding neoadjuvant chemotherapy in Mexican women with early breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-26-03.