Mammalian embryonic development is a complex, highly regulated process extending from fertilization to the formation of a fully developed fetus. This process involves critical stages such as cleavage, blastocyst formation, gastrulation, neurulation, somite development, and organogenesis. In mammals, including humans, development occurs in vivo, limiting direct observation of intermediate stages due to technical and ethical challenges. While animal models offer foundational insights, direct study of human embryogenesis remains crucial for understanding congenital disorders and advancing reproductive and regenerative medicine. This chapter provides a comprehensive overview of human embryonic development through diagrams and photomicrographs to illustrate key stages, based on the standardized Carnegie staging system, spanning 23 stages across the first eight weeks post-fertilization. It provides a standardized morphological framework to describe human embryonic development. Early stages cover cleavage and blastocyst formation, implantation, and bilaminar disc formation. Mid-stages mark the onset of gastrulation, neural induction, and somite segmentation, while later stages involve organogenesis, including brain development, cardiac formation, limb buds, and facial features. By Stage 23, major organ systems are formed, signaling the transition to the fetal period. Visual tools such as photomicrographs and diagrams serve as indispensable educational resources, enabling learners to identify key structures and developmental timelines while circumventing ethical constraints. Studying these stages enhances understanding of normal development and congenital anomalies influenced by genetic and environmental factors. This knowledge supports early diagnosis, improves assisted reproductive technologies, and informs regenerative therapies, ultimately contributing to better reproductive health and management of developmental disorders.