During pre-implantation development, the mammalian zygote transforms into the blastocyst, the structure that will implant the embryo in the maternal uterus. Consisting of a squamous epithelium enveloping a fluid-filled cavity and the inner cell mass, the blastocyst is sculpted by a succession of morphogenetic events. These deformations result from the changes in the forces and mechanical properties of the tissue composing the embryo. Here, I review the recent studies, which, for the first time, informed us on the mechanics of blastocyst morphogenesis.