Acute appendicitis is the most common urgent pathology in general surgery. Under the «mask» of acute appendicitis, rare forms of appendix disease are sometimes operated on, one of which is mucocele. Appendiceal mucocele is a relatively rare disease that occupies no more than 8% of cases of neoplasms of the appendix, which is a pseudotumor that develops as a result of stretching the lumen of the appendix, in which a large amount of mucous contents (mucin) accumulates. In most cases, mucocele is asymptomatic or with nonspecific manifestations. Considering the rarity of the disease and the complexity of diagnosis during the pandemic, we present a clinical case of laparoscopic appendectomy for appendiceal mucocele in patient with COVID-19. A 44-year-old patient with symptoms of acute appendicitis and a positive result of the polymerase chain reaction for Sars-Cov-2 with bilateral polysegmental pneumonia, diagnostic laparoscopy revealed 150 ml cloudy, jelly-like effusion in the right iliac region, the appendix is 8.0×4.0×3.0 cm with a wide base and inflamed walls, in the apex there is a perforation and leakage of a jelly-like mass. Laparoscopic appendectomy, sanitation and drainage of the abdominal cavity were performed. The results of histological examination revealed an appendiceal mucocele and suspicion of cryptococcosis. During an in-depth study of the removed specimen at the Kashkin Research Institute of Medical Mycology did not receive any data for cryptococcosis. Given the high risk of developing pseudomyxoma peritonei, the patient is periodically observed in the hospital. During control examinations every 6 months, no pathology is detected. Thus, despite its relatively rare occurrence, mucocele may be one of the factors in the development of clinical scenarios requiring appendectomy. In urgent surgery, it is necessary to be able to switch to the standards of treatment of neoplastic lesions with the implementation of an interdisciplinary approach.