Background: Electroconvulsive therapy (ECT) is an effective treatment for older patients with severe psychiatric disorders, but their knowledge and attitudes regarding ECT have not been well studied. This study examined the knowledge and attitudes of older Chinese patients and their caregivers towards ECT. Method: A total of 216 participants comprising older patients treated with ECT (n = 108) and their caregivers (n = 108) were recruited. Their knowledge and attitudes regarding ECT were assessed using self-reported questionnaires. Results: Most caregivers received sufficient information on the therapeutic effects of ECT, but inadequate information about the ECT process, its adverse effects, and risks was provided to caregivers and patients before treatment. Although ECT was generally viewed as beneficial, effective, and safe, around two-thirds of patients and caregivers believed that ECT should be used only for critically ill patients. Over half of the patients reported adverse effects caused by ECT, with memory impairment being the most commonly reported. Conclusions: Clinicians in Chinese psychiatric hospitals need to provide sufficient information on ECT to older patients and their caregivers before treatment, particularly regarding the treatment process and adverse effects.