A serological inquiry was performed in the municipality of Sena Madureira, Acre State, Brazil, to evaluate the individual contact with Echinococcus sp. The participants were recruited from two distinct populations: residents in the urban and rural areas, the latter distributed among riverside communities of the region. A total of 1,064 individuals were evaluated: 851 from the urban zone and 213 from the rural area. The study was divided into two phases: a serological screening, in which the blood samples were collected and then sent to the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (Serology Laboratory), Ribeirão Preto, SP, Brazil, for the serological test by counterimmunoelectrophoresis technique; and secondly an epidemiological inquiry for evaluating the individuals and their dwelling conditions and customs. Comparing the results of serological tests, the prevalence in the rural area was 6% against 3.5% in the urban area. The overall prevalence was 4%. The possibility of the existence of another intermediate host in the life cycle of Echinococcus vogeli was analyzed and the findings indicated the domestic pig as being the most probable.