Purpose Breast cancer (BC) is the most common cancer among women in Latin America, yet many countries lack the capacity to provide early detection and diagnostic services. In Peru, mammograms are not readily available in secondary cities, and 57% of women who are diagnosed with BC are diagnosed with stage III and IV disease. To bring services to women in a northern region of Peru, PATH collaborated with Peruvian health institutions at the local, regional, and national levels to design and implement a strategic algorithm with which to increase the early detection of BC in the absence of mammography. Here, we evaluate the impact of training on the quality of clinical breast exam (CBE), ultrasound triage, and fine-needle aspiration (FNA) sampling and the reading of FNA biopsy for triage-positive women. Methods Two hundred twenty-four midwives and 15 doctors were included in two-step training in Trujillo, Peru. CBE trainings were performed using anatomic models and patient exams in 2-day sessions. Team discussion with trainers was used to improve skills. Doctors’ trainings for FNA sampling were led by two international expert pathologists in 2014 and by a Peruvian expert pathologist in 2016. Then in 2017, 43 pretraining and 50 post-training FNA biopsy samples were evaluated for adequacy and quality of diagnosis. Results Since the trainings, 14,223 women have received CBE on an opportunistic basis. Midwives refer abnormal cases (n = 281) for follow-up. All doctors felt well trained for CBE and FNA, whereas five of 15 doctors perceived the need for additional ultrasound training. Quality assessment revealed that the adequacy of FNA samples improved from 26% pretraining to 37% post-training. Of the 43 FNA samples, a low concordance with reviewers was observed in the detection of suspicious/carcinoma (6.9% v 13.9%), whereas full concordance was observed after the training, although the numbers were small. Conclusion In Peru, CBE remains an acceptable and feasible approach if complemented with ultrasound triage and FNA biopsy. Additional efforts are needed to increase coverage through a structured program. Training and continuous monitoring are essential for quality assurance. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO's conflict of interest policy, please refer to www.asco.org/rwc or ascopubs.org/jco/site/ifc . Ronald Balassanian Stock or Other Ownership: Cerus Corp ($400.00)