Fruit (mericarp) and seed morphology of 11 species and two subspecies of Galium were examined with light microscope and scanning electron microscope. Macro- and micromorphological characters, including fruit and seed shape, colour, size, surface, epidermal cell shape, anticlinal boundaries, outer periclinal cell wall and relief of outer cell walls, are presented. Four different types of mericarp surface are described. Three types of anticlinal cell wall boundaries of seed are recognized and three different shapes of outer periclinal cell wall are described. The secondary sculpture of the cell wall varies from micro-papillate to micro-reticulate, and smooth to fine- or coarse-folded. The fruit and seed characteristics could be used for taxonomic identification.