A 53-yr-old woman developed contralateral weakness and fatigue, without autonomic symptoms, 2 wks after receiving an injection with 800 units of botulinum toxin A for management of her poststroke spasticity. Although the patient reported resolution 4 wks later, clinical evaluations suggested an even longer time course. The patient then experienced the same contralateral symptoms again more than a year later, after a 500-unit injection, which took a similar length of time to resolve. We report the first known case of repeated contralateral weakness and fatigue after high-dose botulinum toxin A injection. Currently, dosage is largely titrated by the practitioner based on individual patient response. Before performing botulinum toxin A injections for therapeutic purposes, the expected risks and benefits for each patient must be carefully considered.