This study examined whether books that are typically read to preschool children contain theory of mind concepts. The parents of 47 preschool children recorded books read by or to their child over a one-week period. The books were analyzed for theory of mind content. It was found that 78% of the books contained internal state language, 34% contained false beliefs, and 43% contained personality descriptors. Thus, theory of mind concepts appear to be an integral part of the literature read to preschool children. These results are discussed in light of recent work on individual differences in theory of mind development.