As an embryo develops, it is transformed from a single cell into the complex tissues and organs of the adult. Many factors control this process including maternal instructions stored in the egg, the program of development expressed by genes, and the morphogen gradients that form the body axis and segments. However, the intrinsic actions of the cytoskeleton, motor proteins, and cell/cell/matrix adhesions generate mechanical forces responsible for cell shape, polarity, and motility. These forces also act extrinsically to coordinate the large-scale morphogenetic movements of cells into embryonic tissues. While the cell-level mechanics of morphogenesis is becoming well understood, the mechanics of tissue morphogenesis remains unexplored. We have characterized the mechanics of zebrafish gastrulation by mapping areas of large-scale deformation over the zebrafish embryo from mid-epiboly to neurulation. Our maps describe the key steps in gastrulation such as convergence and extension, somatogenesis, and the emergence of left-right symmetry in terms of linear strain and curl.