INTRODUCTION: The primary health care system is the first of the three hierarchical levels of care, and it is the first point of contact of the population with the health system. In Luanda, Angola, the primary care network presents challenges in its management, as well as in the perception of its purposes, which constitutes a serious problem for the demand for health services, being the reason for this study. The present research aimed to evaluate the level of adherence and satisfaction related to the health care system and their influence on usage of the public primary health care facilities in Luanda, from the perspective of health professionals and users. METHODS: A cross-sectional and descriptive study was carried out on 120 health professionals and 423 users. RESULTS: We found a statistically significant association between the level of education and the professionals' disbelief in health services (P = 0.001), as well as the users' family income (P = 0.0002). DISCUSSION: The users' perception is that there is a switch in test results (P = 0.01). Furthermore, they also believe that when attending health units, the user leaves sicker than he entered (P = 0.01). CONCLUSION: Thus, it was found that the level of user adherence to the services of the primary health care units in Luanda ranged between "good" and "acceptable". We identified elements capable of compromising the quality of services and, consequently, interfering with adherence to them, which suggests the need for the development of management strategies for health facilities, in order to overcome the challenges presented in the study.