The objective was to analyze the perceptions of primary health care (PHC) workers about interprofessional collaboration from the perspective of implementation science. This is a qualitative study that used in-depth interview as a data production technique. Interviews were conducted with 15 workers (three community health agents, one nursing assistant, three nurses, three managers, three physicians, and two nursing technicians) from basic health units in the Municipality of São Bernardo do Campo, São Paulo State, Brazil. The interview plan was based on three domains of the Consolidated Framework for Implementation Research (CFIR). Thematic content analysis was used. In the interprofessional collaboration characteristics domain, respondents highlighted the complexity, and its possible influence, as to the implementation and sustainability of this practice. In the inner setting domain, factors that influence interprofessional collaboration were identified, namely: how the time allocated to formal communication/team meetings is used; social interactions between professionals; and leadership characteristics, such as feedback, autonomy and participation in decisions. In the individuals characteristics domain, participants noted interprofessional collaboration geared to quality of care and the need for integration between knowledge centers. Thus, measures to enhance the quality of communication, collective team building and leadership can contribute to improve interprofessional collaboration in PHC and leverage its impacts on health care.