Introduction: Diverticular disease of the appendix is an infrequent finding in the study of surgical specimens from patients operated on for clinically suspected acute appendicitis. Our aim was to determine the prevalence of diverticular disease of the appendix in patients who underwent appendectomies based on the clinical diagnosis of acute appendicitis. Material and Method: Design: Cross-sectional study. Inclusion criteria: Patients who underwent appendectomies based on a clinical diagnosis of acute appendicitis. Study period: january 2000 to december 2008. Sampling: Non-probabilistic sampling of consecutive cases. Methodology: A review was conducted of the clinical records and surgical specimens from patients who underwent appendectomies based on a clinical diagnosis of acute appendicitis. Results: Within the study period, 11.472 appendectomies were performed based on a clinical diagnosis of acute appendicitis. Ninety-four patients presented diverticular disease of the appendix (0.8%). The median age was 40 years and 62.8% were male. The disease appeared as: appendicular diverticulitis (45.7%), appendicular diverticulosis with acute appendicitis (28.7%), appendicular diverticulitis with acute appendicitis (17.0%), appendicular diverticulosis (5.3%), and appendicular pseudodiverticulosis with acute appendicitis (3.2%). Operative morbidity was 12.7%. One patient presented an adenocarcinoma of the appendix associated with diverticular disease. Conclusion: The prevalence of diverticular disease of the appendix is low in our population and the characteristics are different to reported by other authors.