Acute appendicitis is the most common abdominal surgical emergency in children. In order to determine the related factors for early diagnosis of acute appendicitis in children, we analyzed retrospectively from January 2001 to December 2002 the hospital records of 260 consecutive patients under 18 years of age operated on because of suspected acute appendicitis. The patients group comprised 163 males (62.7%) and 97 females (37.3%) with a mean age of 11.1 +/- 4.3 years (range from 0 to 18 years old). The accurate diagnostic rate of acute appendicitis in children was 81.5 percent and negative appendicectomy rate was 18.5 percent. When combining leukocytosis, elevated neutrophil count and elevated C-reactive protein, the specificity and positive predictive value in diagnosing acute appendicitis were increased. According to the application of multivariate logistic regression analysis, the significantly related factors in acute appendicitis were elevated neutrophil count (Odds ratio = 3.79, 95% confidence interval = 1.732-8.293, p < 0.001) and elevated C-reactive protein concentration (Odds ratio = 2.81, 95% confidence interval = 1.231-6.390, p < 0.05). In conclusion, total neutrophil count and C-reactive protein may serve as predictive parameters for early diagnosis of acute appendicitis in children.