The purpose was, to determine the frequency of infant mortality in the marginal areas of Guadalajara and, find its association with sociodemographic and economical factors, which are known as determinant of the nutritional status of children. There were included 898 families in a cross sectional design among children who applied to the food supplementation program of ONI of Guadalajara. Through an interview and home visit, it was obtained information about sociodemographic and economical characteristics and food habits. The data was recorded and analyzed by the Dbase III Plus and Epi-Info program. It was also used Chi square test and Odds Ratio for the statistical analysis. Education of the mother and income per capita for feeding (as a percentage of the minimum salary) had a significantly and inverse association with infant mortality (P less than 0.0001 and P less than 0.001 respectively). There was also major mortality among children with no social security (P less than 0.05). The Odds Ratio for infant mortality was of 3.02 for education of the father, 8.42 for education of the mother and 6.8 for income per capita for feeding. Meanwhile the level of education and the economical situation of the studied population remain so low, it seems improbable to decrease the rate of infant mortality.