Introduction: Obstruction of the appendiceal lumen is the primary cause of appendicitis. The most common causes of luminal obstruction are fecaliths and lymphoid follicle hyperplasia. Additionally, bacterial infections or enteric and systemic viral diseases can cause a reaction of the lymphoid follicle. Case presentation: An 11-year-old boy with active phase of chickenpox presented on our Pediatric surgery emergency department under the impression of acute appendicitis. An appendectomy was performed on the same day. An inflamed and edematous retrocecal appendix was removed during surgery. Histological investigation of the appendix revealed transmural acute inflammation, with diffuse proliferation of inflammatory cells, with characteristic intranuclear inclusion surrounded by a clear halo. The PCR analysis of peripheral blood and appendix tissue specimen revealed positive VZV DNA. Conclusion: We have shown that varicella-zoster virus infection of the appendix is associated with acute appendicitis and possibly also with severity of the disease., Zenon Pogorelić, Mihovil Biočić, Ivo Jurić, Klaudio Pjer Milunović, Ivana Mrklić, and Literatura 11