In this paper, we study the effects of poor conditions of territories in patient visits performed by community health workers and the consequences to primary care policies. We carried a case study with community health workers in Rio de Janeiro, Brazil, including ethnographic observations in two primary healthcare clinics. Moreover, we present an analysis of the collected data with the support of the function resonance analysis method and we point out relations between the findings and the execution of the primary healthcare policy in a systemic approach. Thus, our study highlights the impacts of work situations in the health assistance of poorly developed communities, indicating how community health workers cope with adverse conditions, and how such situations affect the effectiveness of primary care policies.