Background Coronavirus disease 2019 (COVID-19) is a contagious disease whose symptoms and risk factors are newly described. Some allergic diseases, including asthma, have been defined as risk factors for a poor outcome in COVID-19. We aimed to investigate the role of another allergic disease-allergic rhinitis-in the severity of COVID-19. Methods This case-control study was conducted at Sakarya Educational and Research Hospital, Toyota Hospital and Yenikent State Hospital between March 18, 2020 and August 30, 2020. The study included a case group of 125 randomly selected patients who had been diagnosed with allergic rhinitis in advance of having COVID-19 and a control group of 125 patients without allergic rhinitis who were diagnosed with COVID-19. We evaluated all participants' statuses regarding smoking, symptoms, and hospitalization, as well as the length of their hospitalization and the number of their comorbidities. Results There were no statistically significant differences between the two groups regarding percentage of asymptomatic patients (p = 0.27), presence of smoking (p = 0.068), hospitalization status (p = 0.79), and hospitalization length (p = 0.55). From each group, two patients needed care in an intensive care unit (ICU). One patient from the case group and two from the control group died due to COVID-19. Conclusion We found that allergic rhinitis did not affect the severity of COVID-19. However, we recommend that the literature be augmented with further studies on the COVID-19 prognosis of patients who have allergic rhinitis.