Background: The true incidence rate of appendicitis in Nigeria and the magnitude of appendicular fecaliths as a specific causal factor in appendicitis are unknown. Materials and Methods: A retrospective clinicopathologic study was conducted using the medical database of the Ahmadu Bello University teaching hospital, Zaria, northern Nigeria for the decade from 2001 to 2010. The National Population Census in Nigeria 2006 was used to estimate the standardized annual incidence of appendicitis in the locality. Pathologically confirmed specimens of appendicitis were analyzed against demographic data of the patient. Results: During the decade, there were a total of 382 cases with intraoperative diagnosis of appendicitis of which the diagnosis was confirmed pathologically in 373 cases. With a local population whose disease or specimens would most probably end up in this hospital pathology department estimated at 1,423,469 the standardized incidence rate of appendicitis was 2.6 per 100,000 per annum. In 354 (93%) out of the 382 specimens, fecaliths were identified and thought to be causally related to the disease in the individual case. Conclusion: Appendicitis is very uncommon in northern Nigeria and when it occurs, it is almost always caused by fecaliths.