BACKGROUND Acute appendicitis is the most common cause of acute abdomen in children. The rate of appendicular perforation may be related to duration from the onset of symptom presentation to treatment. OBJECTIVE To describe the clinical characteristics and assess symptom duration as a risk factor for perforation in children with acute appendicitis. PATENTS AND METHODS: A retrospective analysis of medical records of 322 children under 15 years of ages with intraoperative diagnosis of acute appendicitis between the periods of September 2006 and August 2010. RESULTS Acute appendicitis accounted for 87.5% of all cases of acute abdomen during the study period. Two hundred patients were boys and 122 patients were girls giving male to female ratio of 1.6:1. The mean and median ages were 10.4 and 11 years respectively. The youngest patient was 3 years old. The peak age range was 10-14 years. The most common presenting symptoms were abdominal pain (100%), anorexia (85.1%), vomiting (83.9%), and fever (82.3%). Right lower quadrant tenderness was the leading physical finding observed in 83.9% of patients. The mean duration of symptoms in children with non-perforated appendicitis was 2.5 days whereas the mean duration of symptoms in children with perforated appendicitis was 5.2 days. The mean length of hospital stay in children with non-perforated appendicitis was 3.6 days whereas the mean length of hospital stay in children with perforated appendicitis was 8.4 days. Leucocytosis was observed in 74.5% of children and the mean leucocyte count was 13150/mm3. The incidences of perforation if symptoms were present for less than 24 hours, 24-48 hours and more than 48 hours were 4.1%, 10.2%, and 45.3%, respectively. Postoperative wound infection was observed in 1.9% and 31% of children with non-perforated and perforated appendicitis, respectively. Two children died in the hospital. CONCLUSIONS Acute appendicitis was the commonest cause of acute abdomen in children. It was more prevalent in children aged 10-14 years. The commonest presenting symptoms and signs were abdominal pain, anorexia, vomiting, and fever and right lower quadrant tenderness. The risk of perforation is directly proportional to the duration of illness at presentation. Perforated appendicitis was associated with increased morbidity, mortality and prolonged hospital stay.