Substantial data have accumulated over the past decade indicating that the adult brain is capable of substantial structural and functional reorganization after stroke. While some limited recovery is known to occur spontaneously, especially within the first month post-stroke, there is currently significant optimism that new interventions based on the modulation of neuroplasticity mechanisms will provide greater functional benefits in a larger population of stroke survivors. To place this information in the context of current thinking about brain plasticity, this review outlines the basic theories of why spontaneous recovery occurs, and introduces important principles to explain the effects of post-stroke behavioral experience on neural plasticity. Learning outcomes: Readers will be able to: (a) explain the three classic theories to explain spontaneous recovery after focal brain injury, (b) explain the neurophysiological effects of post-injury rehabilitative therapy on functional organization in motor cortex, (c) readers will be able to describe some of the variables that impact the effects of post-stroke behavioral experience on neuroplasticity, and (d) readers will be able to explain some of the current laboratory-based approaches to modifying brain circuits after stroke that might soon be translated to human application.