Since the introduction of electroconvulsive therapy (ECT) in 1938, research studies in animals have made significant contributions to the clinical practice of ECT. In our search for the underlying mechanism by which ECT exerts its therapeutic and adverse effects, animal studies have yielded additional clues. This paper reviews existing animal literature on electroconvulsive seizures (ECS). It emphasizes ways in which animal data informs our clinical practice and illuminates possible mechanisms of ECT's actions. Finally, recommendations are made for future studies in ECS.