Objective: Despite the proven efficacy and safety of ECT, there is still concern about the possible cognitive side effects of ECT in older patients. In this study, we aimed to characterize the long-term cognitive effects of ECT in patients with late-life depression (LLD) from before the start until 4 years after the index ECT course. Methods: Fourty one patients aged 55 years and older with a unipolar depression, referred for ECT, were included. The neuropsychological test battery was assessed prior to ECT, 6 months, 1 year, 2 years, 3 years, and 4 years after the last ECT session. Results: We did not find any statistically significant cognitive changes from before the start to 4 years after ending the ECT course. Although we could not detect cognitive changes at group level, we found clinically important differences on an individual level. Conclusion: Cognitive performance in patients with LLD runs a stable course from before the start of ECT until 4 years after the index course. At an individual level, however, both cognitive decline and improvement can be witnessed. Older patients can tolerate ECT and most of them will not experience long-term cognitive side effects.