Optical coherence microscopy (OCM) is a novel approach to fluorophore-free 3D live imaging of cells, particularly mammalian oocytes and embryos. It allows for 3D high-resolution visualization of the intracellular architecture: nuclei with nucleoli, metaphase spindles, and networks of membranous structures. Moreover, as it is compatible with time-lapse imaging, it enables monitoring and quantitative analysis of the dynamic behavior of these organelles over time. Importantly, OCM, when imaging settings are properly optimized, is safe for oocytes and embryos and does not negatively affect their developmental capabilities. Therefore, OCM is an interesting alternative to currently used imaging techniques, not only in basic research but also in clinical applications. In the present chapter, we describe the main principles of spectral OCM and show how this technique can be applied to visualize mouse oocytes.