Introduction: Cuiaba presents a huge number of cases of dengue in the endemic periods as well as in the cyclical epidemics. The aim of the study was to analyze the intra-urban differentials of the incidence in 2007 and 2008 relating them with socio--economical and environmental life conditions. Method: study of ecological approach using secondary data. The characterization of the life conditions was gotten from the Demographic Census (IBGE, 2000) and the epidemiologic data from the Surveillance National System (SINAN). The socio-economical index was based on school level and income of the head of family and overcrowding; the socioambiental index used information about sanitation and proportion of precarious domiciles. The variables were classified in quintis and points were attributed for each one. The score for neighborhood was resultant of the addition of the points for each variable. The neighborhoods had been classified in stratus of risk from the combination of results of the two indexes. Results: The incidence was lesser in stratus of average and low risk and very high in the stratum of the highest risk but was bigger then expected in the stratum classified at minimum risk indicating dissociation between life conditions and occurrence of the illness. Conclusion: Higher incidences of the dengue fever in Cuiaba in 2007 and 2008 have been observed in places with precarious conditions of sanitation and inhabited by populations with lesser level of income and education level but there is no linear correlation between life conditions and incidence.