Introduction: Eosinophilic gastroenteritis is characterized by eosinophilic infiltration of GI tract and various gastrointestinal symptoms. Some cases, ascites was observed in serosal type of eosinophilic gastroenteritis, had been reported. However, the cases of eosinophilic gastroenteritis accompanied with pleural effusion are rare. Case report: A 14-year-old male were transferred with abdominal pain, pleural effusion, and peripheral eosinophilia. He suffered from vomiting, abdominal pain, and watery diarrhea for 2 weeks. He had atopic dermatitis. On admission, physical examination revealed abdominal distension with mild tenderness on epigastric area and lower abdomen. In laboratory findings at the time of admission, WBC count was 23,420/mm3 with 49% eosinophils and total eosinophil count was 11,540/mm3. Parasite specific antibody and stool exam were negative. There was pleural effusion on chest radiography and ascites on abdominal CT. Endoscopy of the upper GI tract showed mild mucosal edema with erythematous change on antrum and the lower GI tract showed mucosal edema on entire colon and loss of mucosal vascular pattern with erosive mucosal change. Endoscopic biopsy revealed microabscess of eosinophil on esophagus and eosinophils more than 30/HPF were infiltrated on antrum, duodenum, and colon. Total IgE level was 1040 kU/L and specific IgE of D. farinae and alternaria were ＞100 kU/L and 0.74 Ku/L, respectively. Conclusion: We report a case of eosinophilic gastroenteritis with pleural effusion and ascites shown with sensitization to aeroallergen.