Biological responses to environmental effects are mediated through epigenetic changes such as chemical modifications of the histone tails and DNA (5-cytosine) methylation. We report that dietary protein restriction in pregnant mice can alter histone modifications in the promoter region of the Igf2 gene and cause a two-fold repression in promoter specific Igf2 transcription in the liver of the fetus. Suppression of Igf2 is accompanied with low birth weight of the pups born to the protein-restricted dams. Our results provide new information about the epigenetic aspects of early life programming and will improve our understanding about the developmental origins of adult diseases.