In 1977, Michael Lipton proposed the urban bias thesis as an explanatory framework to existing disparities in developing countries: how overdevelopment of urban areas against underdevelopment of rural distinguishes main gaps in living conditions. We use Life expectancy decomposition analysis on vital statistics on eight Latin American countries (Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru, Venezuela) to determine the relevance of urban bias in life expectancy at all ages during the first decade of the twenty century. For this analysis, “urban” is recognized as a continuum category instead of a dichotomous concept; hence we build and compared city-size groups for each country. Preliminary result points out: life expectancies are higher in the main cities for all countries; differences rely on previous gains in infant mortality and recent improvements in older age mortality levels. At higher levels of urbanization, higher levels of life expectancy and smaller are city-size groups’ gaps.