In Porto Alegre, Rio Grande do Sul State, Brazil, public primary healthcare (PHC) is provided by traditional Basic Health Units (BHU), the Family Health Strategy (FHS), the Murialdo Health Center (MHC), and the Community Health Service (CHS) of Grupo Hospitalar Conceição. This study compares the quality of adult healthcare among these different types of services. Quality of care was measured by interviews focusing on the experience of physicians and nurses in the services (n = 340), using the Primary Care Assessment Tool. Overall scores for the FHS, MHC, and CHS were significantly higher than for the BHU. The CHS also showed a significantly higher overall score compared to the FHS and MHC. In the multivariate analysis, the variables "specialized training in PHC" and "continuing education" were associated with high overall score. Thus, expansion of FHS coverage and investment in professional training are important potential strategies for improving PHC in Porto Alegre.