The COVID-19 pandemic has given more relevance to identifying the common and specific competencies of specialized nurses in community health and public health, presenting and characterizing their interventions, relations with health indicators in the population, identifying factors that facilitate their performance, and their respective regulations. A qualitative case study was undertaken with 31 nurses from a group of health centers and data collection by interviews, direct observation, and documents analysis. The flow model and an interpretive matrix, with two strategies and two techniques, was used for the analysis and discussion. The majority of participants were female, who were aware of and familiar with the specific and defined competencies, which they put into practice. They recognize their activities as important and feel happy where they are and doing what they do. They have good a knowledge of the regulations that concern them. They consider themselves well prepared and available to intervene in many dimensions, such as epidemiological surveillance, management, and group empowerment, contributing to good health indexes and health sustainability. Expected changes are related to their potential contributions to advance the nursing profession, which this pandemic has highlighted.