Introduction: Actinomycosis is a chronic progressive suppurative disease commonly caused by Actinomyces israelii. Abdominopelvic actinomycosis is rare and the appendix is the most common organ involved. Here, we would like to share a case of actinomycosis presented as acute appendicitis in a child. Case report: A 13-year-old boy presented with 5 days history of colicky periumbilical and right iliac fossa pain which was associated with fever and vomiting. He was febrile on examination. There was rebound tenderness on right iliac fossa. His blood count showed leucocytosis with neutrophils predominant. Acute appendicitis was suspected clinically and surgery was performed. Intraoperative findings showed an appendicular mass with localized abscess collections. The appendix was enlarged with macerated mesoappendix. Histology of the appendicular tissue showed acute appendicitis with dense suppurative inflammatory exudates seen in the outer appendicular wall, serosa and mesoappendix with abscess formation. Actinomyces colonies with typical sulphur granules and inflammatory exudate are seen in the lumen. Discussion and conclusion: Abdominopelvic actinomycosis may have resemblance to other disease such as acute appendicitis, diverticulitis or Crohn’s disease. However, histological examination would be able to distinguish them. A combination of long term antibiotic therapy and adequate surgery is necessary to ensure complete eradication. Actinomycosis should be included in the differential diagnosis, especially in patients with abdominal pain, fever, and leukocytosis.