The recent amassing of gene expression data to study development in mammals has led to an increased demand for access to human embryological data. The difficulty of obtaining well-preserved human embryos presents an important challenge to studying human development. The Multidimensional Human Embryo project is generating an image data set based on magnetic resonance microscopy of specimens from the highly respected Carnegie Collection of Human Embryos. The data are available from a web site to facilitate the work of clinicians, investigators, and students of human development. A consequence of the project will be to preserve a highly respected, yet impermanent, collection of human embryos and minimize the need for collecting new specimens.