Among plant life-history traits, those that constitute the reproductive system are the most influential in governing macroevolutionary patterns and microevolutionary processes. This fundamental role arises because reproductive mechanisms influence genetic transmission, population genetic structure, selection response and patterns of evolutionary diversification. Flowering plants exhibit striking diversity in reproductive traits with closely related species often possessing different pollination and mating systems. Shifts in components of plant reproduction are often functionally associated with contrasting life histories and genetic systems indicating the integrated nature of reproductive success. Today, the causes and consequences of repeated transitions in reproductive mechanisms among angiosperm groups are the focus of a major research program in plant evolutionary biology. This is because multiple independent transitions provide outstanding opportunities for identifying the general selective mechanisms responsible for plant adaptation. This special issue of the International Journal of Plant Sciences will highlight a selection of current work by leading authors in the field on the major evolutionary transitions in plant reproduction. Contributions will feature new research findings and synthesis, and will include diverse approaches for understanding major pathways of trait evolution in flowering plants.