Introduction Electroconvulsive therapy (ECT) is an effective depression treatment, but it has potential cognitive side effects. Bitemporal ECT has been traditionally used, but in recent decades, right unilateral (RUL) electrode placement has been proposed to decrease the cognitive side effects of ECT. Ultrabrief pulse (UBP) right unilateral (RUL) ECT is an increasingly used treatment option that can potentially combine efficacy with lesser cognitive side effects. Objectives To evaluate whether ultrabrief pulse (UBP) right unilateral (RUL) electroconvulsive therapy (ECT) is as effective as brief pulse (BP) RUL ECT in addition to cause lesser cognitive side effects. Material and methods A search is performed in the available scientific literature on systematic review and meta-analysis of the subject under study, through the database PubMed. Results – Current evidence supports the efficacy of right unilateral (RUL) electroconvulsive therapy (ECT) given with an ultrabrief pulse width in the treatment of depression; – ultrabrief pulse RUL ECT leads to lesser cognitive side effects than traditional forms of ECT; – ultrabrief pulse RUL ECT may be slightly less effective than traditional forms of ECT. Conclusions BP compared with UBP RUL ECT was slightly more efficacious in treating depression and required fewer treatment sessions, but led to greater cognitive side effects. The decision of whether to use BP or UBP RUL ECT should be made on an individual patient basis and should be based on a careful weighing of the relative priorities of efficacy versus minimization of cognitive impairment. Disclosure of interest The authors have not supplied their declaration of competing interest.