Laboratory research during the past decade has begun to provide insights into the neurobiologic basis of functional recovery after brain injury. It is clear that drugs influencing specific neurotransmitters also can influence the recovery process. Some of these drugs may be beneficial, but others may be detrimental. Some of the difficulties in interpreting the results of these behavioral studies are reviewed, and potential mechanisms of drug effects are discussed. These types of studies are leading to an increased awareness of the potentially harmful effects of some drugs often given to stroke patients. Pharmacotherapy designed to enhance functional recovery after stroke may be possible in the future.