Background: Electroconvulsive therapy (ECT) is effective in treating adolescents with severe psychiatric disorders. This study examined the knowledge, experiences and attitudes of adolescents with severe psychiatric disorders and their caregivers towards ECT in China. Methods: A total of 158 participants, including 79 adolescents who received ECT and their caregivers (n = 79), were enrolled in this study. Their knowledge and experiences about and attitudes towards ECT were evaluated with self-administered data collection forms. Results: Only around half of patients and caregivers reported that they received sufficient information about the process, the therapeutic and side effects, and the risks of ECT, although most believed that ECT is beneficial, and around half believed that ECT is safe. Around one third of patients and caregivers reported that only critically ill patients should receive ECT. More than half of patients experienced side effects, such as memory impairment, headache and short-term confusion. Conclusions: Sufficient information about ECT should be provided to adolescents with severe psychiatric disorders and their caregivers prior to treatment, with particular focus on the treatment process and possible side effects.