Introduction: Primary epiploic appendagitis, a relatively rare and self-limiting disease, of-ten clinically mimics conditions of the acute abdomen such as acute appendicitis and acute diverticuli-tis. It is important to make accurate diagnoses because its treatment is conservative. Ultrasonography and computed tomographic studies enable a reliable diagnosis to prevent unnecessary invasive proce-dures. Herein, we report a case of primary epiploic appendagitis of the appendix vermiformis with clinical, laboratory and CT findings to improve awareness of this condition. Case Presentation: A 29-year-old female presented with acute abdominal pain in the right lower quad-rant. Her medical history was not significant for surgery. She had no nausea, vomiting, diarrhea or fever. On physical examination, she had right lower quadrant tenderness with mild defense and re-bound upon palpation. The leukocyte count (6300 mm-3) and other laboratory parameters, including urine tests, were unremarkable. With these findings, the provisional diagnosis of acute appendicitis was made, and a CT examination (Mx 8000 IDT 16, Philips, USA) was done upon the request of the referring physicians. The abdominal CT showed normal appendix vermiformis. However, a fat density lesion surrounding a hyperdense rim was seen adjacent to the appendix vermiformis. The diagnosis of PEA was thus established based on the characteristic radiologic findings. The patient was managed conservative treatment with pain medication as an outpatient. After a one-week follow-up, the patient was observed to be symptom-free and concluded to have recovered fully from their physician. Conclusion: To conclude, PEA needs to be considered by emergency clinicians and radiologists in the differential diagnosis of acute abdominal pain. With this in mind, it becomes easier for a substantive diagnosis to be made by ultrasound alone or combined with CT to prevent unnecessary surgical inter-ventions, antibiotherapy and hospitalization.