This study aimed to analyze the best practices implemented in primary healthcare (PHC) services and their defining criteria, according to the perceptions of managers, healthcare professionals and users. The theoretical framework of integrality, in three meanings: organization of the services, practices of the healthcare professionals and governmental policy, allowed the characterization of the best practices in PHC and their criteria. This was a qualitative, exploratory, descriptive and analytical study, based on Grounded Theory. Interviews were conducted with seven coordinators, ten healthcare professionals and twelve users of healthcare centers in Florianopolis, Brazil, comprising three sample groups. Two categories of analysis dealing with the meaning of best practice resulted. Perceptions were related to the context and the interactions established between social actors, who prepare their positions based on their experience and positions held in healthcare services.