G-protein coupled receptors represent the largest class of drug targets. Although they serve as targets for about 30% of the known drugs, many of them is still orphan. In the last 15 years, however, we witnessed dramatic developments in the structural biology and pharmacology of GPCRs. High resolution X-ray and cryo-EM structures made the design of the GPCR ligands more rational. The widening knowledge on their signalling resulted in new concepts such as allosteric modulation, GPCR residence time and biased signalling currently tested in clinical trials. This course will provide an introduction for medicinal chemists to this important target class including concepts and methods applied in the structural biology, modelling, systems biology, pharmacology and medicinal chemistry of GPCRs. The course will finish with a series of medicinal chemistry case studies, including the discovery of molecular probes, tool compounds, clinical candidates and marketed drugs.