Eosinophilic gastroenteritis is a rare gastrointestinal disorder characterized by nonspecific gastrointestinal symptoms, peripheral eosinophilia, and eosinophilic infiltration of the intestinal wall. The disorder is classified into mucosal, muscular, and subserosal types, depending on the depth of eosinophilic infiltration within the gastrointestinal wall, and the clinical picture varies accordingly. Subserosal disease, which is complicated by ascites, usually results in the most severe clinical form of eosinophilic gastroenteritis and mandates early corticosteroid therapy. In such cases, a favorable outcome can be achieved after a short course of corticosteroids. We present a rare case in a 43 year-old man in whom eosinophilic gastroenteritis spontaneously resolved without any medical treatment. After reviewing the literature and excluding secondary causes of eosinophilic gastroenteritis, we concluded that this may be the first reported case of spontaneous resolution of primary subserosal eosinophilic gastroenteritis.