The first lineage decisions during mouse development lead to establishment of embryonic and extraembryonic tissues. The transcription factor Cdx2 plays a central role by repressing pluripotency genes, such as Oct4 and promoting trophoblast fate at the blastocyst stage. Here we show that the transcription factor Gata3 is coexpressed with Cdx2 in the blastocyst and that overexpression of Gata3 in embryonic stem cells is sufficient to induce expression of trophoblast genes. Gata3 expression in the blastocyst does not depend on Cdx2, nor do Gata3 overexpressing cell lines require Cdx2 for expression of a subset of trophoblast genes. In the embryo, expression of Gata3, like Cdx2, depends on Tead4, and expression of both factors becomes restricted to nascent trophoblast by an Oct4-independent mechanism. These observations place Tead4 at the top of a trophoblast hierarchy, with Gata3 and Cdx2 acting downstream to induce expression of common and independent targets in this lineage.