BACKGROUND Botulism is an acute neurologic illness characterized by cranial nerve palsies and descending flaccid paralysis. Botulism is a rare disease and recurrent botulism even more rare. We review cases of recurrent wound botulism (WB) among injection drug users (IDUs) in California from 1993 through 2006 and describe 2 case patients. METHODS From botulism surveillance data for 1993-2006, we identified patients with >1 episode of clinical WB, defined as acute descending paralysis with a visible wound or recent history of injection drug use. For each patient, ≥1 of their WB episodes was laboratory confirmed. We extracted demographic, clinical, and laboratory information from case and laboratory reports and compared clinical characteristic frequency of initial and second WB episodes. RESULTS During 1993-2006, 17 IDUs had recurrent WB, 14 with 1 recurrence and 3 with 2 recurrences. Of 25 laboratory-confirmed episodes, 22 were confirmed through serum testing and 3 through wound testing. Patients were 32-61 years old, and 94% were male. All patients reported heroin injections; 88% specified black tar heroin use and 76% reported subcutaneous injection. The most common presentations were having a visible wound, speech difficulty, double vision, respiratory difficulty, and trouble swallowing. There were no significant differences in clinical presentation between initial and second episodes. CONCLUSIONS As the California epidemic of WB among IDUs continues, WB episodes are recurring. Both clinicians and IDUs should be aware of the potential for WB to recur among IDUs to enable timely diagnosis and early botulinum antitoxin administration and supportive care.