This tutorial review presents a description of the controlling elements of intermolecular C–H functionalization by means of C–H insertion by donor/acceptor rhodium carbenes. These rhodium carbenes, readily derived from the combination of diazo compounds with dirhodium(II) catalysts, are sufficiently reactive to undergo a wide range of C–H insertions. They are also capable of highly selective reactions, controlled by a combination of steric and electronic factors. An overview of the structural factors that influence site selectivity will be given, followed by a description of the exceptional diastereo- and enantioselectivity that can be achieved. Several examples will be shown of how this methodology can be applied to streamline the synthesis of natural products and pharmaceutical targets.