To examine disease and treatment characteristics of patients with schizophrenia treated with electroconvulsive therapy (ECT). We examined charts from 79 patients diagnosed with schizophrenia (n = 55), persistent delusional disorders (n = 7), and schizoaffective disorders (n = 17) between 2003 and 2008. We recorded age, sex, indication for ECT, number of ECT sessions, ECT series, outcome, maintenance ECT, use of antipsychotics, duration of illness, and duration of the current exacerbation. All patients were taking antipsychotics at the time of enrolment in the study. Acute ECT included 2–26 sessions; maintenance ECT (M-ECT) was given to 18 patients for up to 12 years. Initial indications for ECT included psychosis (n = 28), pronounced affective symptoms (n = 28), delirious states (n = 20), and M-ECT (n = 3). Most patients experienced excellent/good outcomes (n = 66), but others experienced moderate (n = 8) or poor (n = 5) outcomes. No factors were identified that predicted treatment responses in individual patients. ECT proved to be effective in a population of patients that were severely ill with treatment-refractory schizophrenia. This does not imply that the patients were cured from schizophrenia. Rather, it reflects the degree of relief from psychosis and disruptive behaviour, as described in the patient charts. The treatment was often offered to patients after considerable disease durations.