This study aims to conduct a descriptive analysis of the clinical features and treatment responses in 6 patients with catatonia who received maintenance electroconvulsive therapy (ECT). Our study included all patients who underwent maintenance ECT (mECT) at the Hospital Clínic de Barcelona between September 2020 and September 2022 following a catatonic episode. The study cohort comprised 5 patients with schizophrenia and 1 patient with major depressive disorder. Among patients with schizophrenia, the first catatonic episode occurred several years after their initial paranoid psychotic episode, whereas the patient with depression experienced a rapid progression from the first depressive episode to catatonia. After acute ECT, 4 patients achieved complete symptomatic remission, 1 patient exhibited a partial response, and another maintained a severe catatonic state. Maintenance ECT was indicated because of the high risk of severe relapses. The mean frequency of mECT sessions was 9.83 (SD, 5.60) days. Notably, 66.67% of the patients were concurrently receiving clozapine as part of their pharmacological treatment. Among patients with schizophrenia, mECT sessions could not be extended beyond 7 to 10 days, whereas the depressed patient could space ECT sessions up to 21 days without experiencing a relapse. Maintenance ECT proves to be a safe and well-tolerated strategy for preventing relapses in severe catatonic patients who have previously stabilized with acute ECT. Further research is needed to develop clinical guidelines that define optimal application strategies for mECT in catatonia.