In hybrid corn seed production fields, the action of the female parental polen provides a great deal of sefings, stablishing the main source of genetic contamination. The objective of this study was to evaluate the physiological qualíty of hybrid seed lots presenting mixtures of seeds obtained from different degrees of the female parental selfing. For the study, hybrid seeds and selfed female parental seeds were produced from the single hybrid C 901, the three way hybrid C 808A and from the double cross hybrids C 425 and C 01. After obtaining the material, seeds deriving from the selfed female parental were mixed with the corresponding hybrid seeds under four different rates: 0, 5, 10, 20, 100%. These samples were evaluated for their physiological quality in the seed lab of the Escola Superior de Agricultura ?Luiz de Queiroz? a branch of the University of São Paulo by the following test: germination percentage, accelerated aging, cold, eletrical conductivity and field emergency. The hybrids C 701, C 425 and C 808A, presenting a mixture of seeds from the selfed female parental with its respective hybrid seeds did not show reduction on physiological quality. However lots from the single hybrid C 901, showed reduction on the physiological quality in order to the different rates of mixture.