In 2020, a total of 2,510 new cases of breast cancer were estimated in Ceará State, 14% above the figures of 2019. In the context of the COVID-19 pandemic, postponing screening and assessing the risks and benefits of elective procedures was needed, rescheduled until after their control. We sought to identify the impact of the COVID-19 pandemic in the care of a Reference Service for Breast Cancer Diagnosis. Time series study, with analysis of the production of the consultations carried out from March to June of the current year in a service located in Fortaleza City, Ceará State. There was a reduction of up to 84% in the services offered, with emphasis on mammography and ultrasound procedures, with 95 and 100%, respectively. The diagnosis of new cases and the performance of surgeries reduced by up to 60 and 56%, respectively. The months with the greatest impact were April and May, with a progressive resumption in June. The study evaluated a reference service of relevance in the state reality. Considering that many cases are identified during screening, postponing mammograms contributed to a delayed diagnosis. The findings are believed to pose severe consequences, considering the annual increase in the incidence of the disease, the low screening coverage, the high number of cases in advanced staging, the ascending mortality, and the low supply of diagnostic services. Diverting attention exclusively to the pandemic represents a worldwide challenge, but cancer is an important cause of morbidity and mortality, and cannot be neglected. There is concern that delaying screening, diagnosis, and treatment of breast cancer may cost more lives than COVID-19 itself. Post-pandemic requires planning to promote harm reduction resulting from the delay in the diagnosis and treatment of the repressed demand, in a disaggregated and overloaded system.