GABAergic interneurons play crucial roles in regulating the function of the cerebral cortex and their dysfunction, a potential mechanism underlying epilepsy and cognitive deficits in many neurodevelopmental and psychiatric disorders. A hallmark of cortical interneurons is their remarkable structural and functional diversity, yet we are only beginning to understand the cellular and molecular determinants underlying their distribution, wiring, and plasticity. In this talk, I will provide an overview of our current work on the mechanisms regulating the generation of the remarkable diversity of GABAergic interneurons, the control of their number, and their assembly into specific circuits in the cerebral cortex.