Electroconvulsive therapy (ECT) remains the most effective treatment of depression in the elderly population; however, it is still unclear which type of ECT is most beneficial in this population. The aims of this study were: (i) to assess the feasibility of a randomised controlled trial in elderly depressed patients treated with right unilateral (RUL) or fronto-temporal bilateral (BT) formula-based ECT; (ii) to compare formula-based RUL and BT ECT in terms of efficacy, safety and tolerability in this population. The study lasted 3 years and managed to randomise 29 patients over 65 years old to receive either BT (n = 14) or RUL (n = 15) ECT. Brief pulse width (0.5 ms) and age-based dosing method were applied. The clinical efficacy was assessed using Hamilton Depression Rating Scale, somatic state was monitored throughout the ECT course. In neuropsychological examination general cognitive performance, executive functions, verbal fluency, memory, autobiographical memory were evaluated. The recruitment was poor due to small number of patients able to give informed consent. ECT proved to be a highly effective and safe method of treatment among elders. Formula-based RUL ECT did not differ from BT in antidepressant efficacy and had cognitive advantages - the indices of general cognitive performance, verbal fluency and memory were significantly better than before the treatment in the RUL group. Decline in retrieval consistency of autobiographical memory was more pronounced in the BT group, although it was observed across both groups. Formula-based RUL ECT might not differ from BT in antidepressant efficacy and has an advantage in terms of tolerability.