The study aimed to analyze the relationship between decentralization of the Brazilian Unified National Health System (SUS) and the development of epidemiological surveillance activities in municipalities (counties) in Pernambuco State, Brazil. This was an exploratory descriptive qualitative and quantitative study, including a document search, completion of semi-structured interviews by key informants, and an ecological spatial and time trend study of selected health indicators, covering a 10-year period (2001-2010). The study showed that municipalities adhered to the decentralization process, which was making progress in Pernambuco, but with inequalities and weaknesses in its development. There was also a fluctuation in the time series for the selected indicators. Thus, even though the decentralization of epidemiological surveillance is still incipient in some municipalities, their protagonist role in implementing the activities promotes empowerment at the local level by producing key information for decision-making.