The Eosinophilic ascites (EA) is a rare disorder of unknown etiology that has been reported in both adult and pediatric patients. It is a part of the eosinophilic gastroenteritis (EGE) syndrome, which is characterized by the presence of non specific abdominal complaints in association with eosinophil-driven inflammation of any or all layers of the gut wall. Peripheral eosinophilia may or may not be present. Here, we report a case of EA, a rare presentation of the serosal variant of EGE that developed in a thirty years old Egyptian female. She complained initially from nonspecific GI symptoms associated with diffuse abdominal pain and distention for several weeks. Her physical examination was significant for moderate ascites. Initial work-up demonstrated: very high peripheral eosinophilia, normal liver function tests, thickening of the small and large bowel walls, and normal total serum IgE. Upper endoscopy and extensive testing for malignancy and parasitic infections failed to establish a diagnosis. Ascetic fluid analysis showed significant eosinophilia. Further, a duodenal biopsy showed marked eosinophilic infiltration of the lamina Propria. This report adds to the scarce data on serosal involvement, "the rarest form of presentation" and illustrates that EGE complicated by ascites can be effectively treated with a combination therapy of steroids and the leukotriene receptor antagonist "Montelukast" after other systemic disorders associated with peripheral eosinophilia have been ruled out. The pathophysiology, differential diagnosis as well as therapeutic challenges associated with EGE are discussed.