Small alkaline or lithium-ion batteries, which are commonly referred to as watch batteries or button cells, may cause potentially dangerous organ injuries and tissue damage if swallowed. This condition, which is commonly seen in children, may cause damage, particularly in the respiratory and gastrointestinal tracts, as well as in the nose, external ear canal, and middle and inner ears. Ulceration due toxin contact is a very rare condition. In this study, we present the case of an 18-month-old male who swallowed a cell which caused damage in the medial femoral area after harmlessly passing through the entire gastrointestinal tract. The battery caused skin necrosis with the contribution of the electrolytic effect of stool in a diaper is an infrequent case and avoidable with only the parents' attention. Usually, swallowing watch batteries does not cause any symptoms or findings, and it easily excreted in stool. However, serious injuries and even deaths in cases involving the nasal cavities, outer and inner ear, esophagus, stomach, intestines, and neighboring organs have been reported in the literature. It is important to acknowledge the negative consequences and signs and symptoms of such conditions, and note that the battery may stick to body parts such as genital, medial femoral, anal, and intergluteal regions that remain in the diaper-covered area and may cause skin ulcerations due to the electrolytic characteristics of the stool