Members of the adhesion G protein-coupled receptor (aGPCR) class have emerged as crucial regulators of nervous system development, with important implications for human health and disease. In this Review, we discuss the current understanding of aGPCR functions during key steps in neural development, including cortical patterning, dendrite and synapse formation, and myelination. We focus on aGPCR modulation of cell-cell and cell-matrix interactions and signalling to control these varied aspects of neural development, and we discuss how impaired aGPCR function leads to neurological disease. We further highlight the emerging hypothesis that aGPCRs can be mechanically activated and the implications of this property in the nervous system.