Frequent aggression toward others and repetitive self-injurious behaviors (SIB) can be features of catatonia in patients with autism. Similar to catatonia secondary to other etiologies, catatonia associated with autism responds well to treatment with benzodiazepines and/or electroconvulsive therapy (ECT). The authors report here on two adolescent patients with autism who presented with severe aggression, one of whom also engaged in repetitive SIB. With ongoing treatment with maintenance ECT, dramatic reduction in aggression and SIB were noted, allowing both patients a reasonable quality of life in their own homes. Attempts to taper off ECT coincided with return of aggression symptoms, although not SIB.