The present study investigated the effects of catalpol, the main constituent of the Chinese herb Rehmannia root, on neurons following brain ischemia. A rat model of focal permanent brain ischemia was established using electrocoagulation. The rats were intraperitoneally injected with catalpol, at a dose of 5 mg/kg, daily for 1 week. Results showed that the number of neuronal synapses in the motor cortex and growth associated protein 43 expression were increased following catalpol treatment, indicating that catalpol might contribute to neuroplasticity and ameliorate functional neurological deficits induced by cerebral ischemia.