Early development is a critical stage in a plant's life, as the plant must establish itself in the ecosystem during this period. The secondary metabolites (SM) during this phase is a strategy that contributes to the survival of plant species. Through a review of the literature, a number of reports were found that investigated the presence of SM during germination and early plant development (phases 0 and 1 according to the Zadoks and BBCH scales). A total of 250 reports were found that investigated 99 species and nearly 200 SM that accumulate during this period of the plant life cycle. A large portion of the SM are biosynthesised de novo, whereas the remainder are derived in part or in total from the mother plant. In many cases, the resources for biosynthesis are supplied only by the reserve material of the endosperm or cotyledons, which allows for independent photosynthesis. The presence of SM at these stages confers characteristics of more advanced stages, such as tissue-specific distribution, spatio-temporal regulation, and the individual regulation of all of the biosynthesised SM. The amount and diversity of SM are not universally related to the progress of plant development, but it is a widespread phenomenon. The early production of SM has ecological implications that involve defence mechanisms, relationships with microorganisms, and the role of these compounds as nitrogen reserves. This review contributes to the systematisation of studies on SM in the early stages of development.