The immune system distinguishes “self” from “non-self”, and “host” from “pathogen”, through its ability to recognize specific arrangements of atoms and molecules. An evolving understanding of the immunochemistry of host-defense has enabled research efforts focused on the construction of synthetic systems that can perform complex immunological functions, an area termed “synthetic immunology”. Research in this area is at the interface between synthetic chemistry and immunology, and encompasses a broad swath of scientific activities. Chapter 1 focuses on one aspect of synthetic immunology – the development of small molecules capable of mimicking the immunological functions of biological molecules. Despite its relatively narrow focus, it covers research relevant to both innate and adaptive immune processes, which has significant potential to illuminate activities ranging from fundamental chemistry and biology to novel therapeutics development. We hope that the science reviewed will serve to inspire interest from an equally broad range of researchers.