Objective. To describe the epidemiological characteristics of malaria and its main determinants in the municipality of Cruzeiro do Sul, State of Acre, Brazil, between 1998 and 2008. Methods. This descriptive, retrospective study was carried out with secondary data available from the malaria information systems developed by the Brazilian Ministry of Health (SISMAL/SIVEP-Malária). The data were analyzed using the TABLEAU® software. Geospatial data were obtained to assess the distribution of malaria cases. Results. The annual parasite incidence (API) of 27 cases/1 000 population in 1998reached 571.5 cases/1 000 population in 2006, the year in which the city recorded its largest epidemics, following the establishment of a state program that encouraged the digging of tanks for fish farming in 2005. Rural sites had the highest number of cases. However, peri-urban locations with fish tanks had higher APIs than peri-urban areas without tanks. Following the strengthening of control actions by the National Malaria Control Program, the API in Cruzeiro do Sul dropped to 152.9 cases/1 000 population in 2008. Conclusions. The type of economic activity fostered in peri-urban areas characterized by unstable malaria transmission, which are typical of Latin America, must be very well planned. Malaria control in Cruzeiro do Sul relied on integrated strategies implemented simultaneously by federal, state, and city governments, as recommended by the National Malaria Control Program. It is important to underscore the usefulness of a reliable information system such as SIVEP-Malária to estimate the burden of disease and efficiently monitor the impact of interventions. [ABSTRACT FROM AUTHOR]