Many eukaryotic cell-surface proteins and glycoproteins are anchored to the plasma membrane by glycosylphosphatidylinositols (GPIs), a family of glycolipids that are posttranslationally attached to proteins at their C-termini. GPIs and GPI-anchored proteins play important roles in many biological and pathological events, such as cell recognition and adhesion, signal transduction, host defense, and acting as receptors for viruses and toxins. Chemical synthesis of structurally defined GPI anchors and GPI derivatives is a necessary step toward understanding the properties and functions of these molecules in biological systems and exploring their potential therapeutic applications. In the first part of this comprehensive article on the chemical synthesis of GPIs, classic syntheses of naturally occurring GPI anchors from protozoan parasites, yeast, and mammals are covered. The second part of the article focuses on recent diversity-oriented strategies for the synthesis of GPI anchors containing unsaturated lipids, " click chemistry" tags, and highly branched and modified structures.