Mycobacterium chelonae usually causes soft-tissue and skin infection. It is a rare cause of otomastoiditis. The clinical presentation and operative findings are similar to those of other nontuberculous mycobacterial infections. We describe a case of left-sided otomastoiditis with acute facial nerve paralysis caused by this organism in a previously well middle-aged woman. Her facial palsy totally resolved after tympanomastoidectomy plus a 7-week regimen of clarithromycin and moxifloxacin. To our knowledge, a case of otomastoiditis with acute facial nerve paralysis caused by M chelonae has not been reported previously.