The µMRI Atlas of Mouse Development is a3D digital atlas of normal mouse development constructed from magnetic resonance image data. An important consideration in the construction of this atlas was the use of MRI for the collection of embryonic images. MRI is a non-destructive imaging modality which derives contrast from the water content and chemical environment permitting the imaging of internal structures of opaque embryos. Specimens are prepared in aqueous, isotonic solutions so there is no tissue shrinkage. Limited specimen handling minimizes physical perturbation of the embryos. The results of this approach is perhaps some of the most accurate geometric representations of developing mouse anatomy available.