AIM: Although the radiological features of acute appendicitis have been well documented, the value of plain radiography has not been fully appreciated. The aim of this study was to determine the frequency of the association of acute appendicitis with images of fecal loading in the cecum.METHODS: Plain abdominal radiographs of 400 patients operated upon for acute appendicitis (n = 100), acute cholecystitis (n = 100), right acute pelvic inflammatory disease (n = 100) and right nephrolithiasis (n = 100)were assessed. The presence of fecal loading was recorded and the sensitivity and specificity of this sign for acute appendicitis were calculated.RESULTS: The presence of fecal loading in the cecum occurred in 97 patients with acute appendicitis, 13 patients with acute cholecystitis, 12 patients with acute inflammatory pelvic disease and 19 patients with nephrolithiasis. The sensitivity of this sign for appendicitis was 97% and its specificity to this disease was 85.3%. Its positive predictive value for appendicitis was 68.7%; however, its negative predictive value for appendicitis was 98.8%.CONCLUSION: The present study suggests that the presence of radiological images of fecal loading in the cecum may be a useful sign of acute appendicitis, and the absence of this sign probably excludes this disease.This is the first description of fecal loading as a radiological sign for acute appendicitis.