The aim of this study was to investigate whether maternal ingestion of oxidized frying oil (OFO) during pregnancy influences the susceptibility to diet-induced obesity (DIO) of the adult offspring. Pregnant C57BL/6J mice were fed either a control diet [10% fresh soybean oil (SO)] or an OFO-containing diet (10% OFO) throughout the entire gestational period. After parturition, all pups were nursed by SO-fed dams for 3 wk, weaned onto a nonpurified standard diet for 4 wk, and shifted to a high-fat diet (29% butter + 1% SO) for 5 wk. Consequently, 4 groups of offspring were obtained, consisting of the male (m) or female (f) offspring of dams fed the OFO diet (OFO-m and OFO-f) or the SO diet (SO-m and SO-f). At pregnancy d 18, higher amounts (P < 0.05) of mRNA for PPARα target genes were found in the liver of the OFO-fed dams and their fetuses than in their SO controls. Although all pups were raised under the same conditions in postnatal life, a comparison based on the gender of pups from dams fed the different diets showed that adult OFO-f mice were prone to DIO, whereas adult OFO-m mice were resistant. The adult OFO-m mice also had higher expression of PPARα target genes in the liver and white adipose tissue (WAT) and of thermogenic genes in the WAT than adult SO-m mice, whereas adult OFO-f and SO-f mice did not differ. We conclude that uterine PPARα activation caused by maternal OFO ingestion affects hepatic PPARα activity and adipose thermogenic capacity and contributes to the differential susceptibility to DIO in the male and female offspring in adulthood.