A 78-year-old male with a history of diabetes and end-stage renal disease on peritoneal dialysis presented with fever, cough, and fatigue due to COVID-19 Omicron virus strain infection. He had been treated with roxadustat for renal anemia, which effectively maintained his hemoglobin levels between 120 and 130 g/L. However, during the Omicron infection, his hemoglobin dropped to 104 g/L, accompanied by anorexia, diarrhea, and weight loss. Hospital admission revealed Omicron virus nucleic acid positivity and a mild form of the infection. Despite the inflammatory state and gastrointestinal symptoms, treatment with roxadustat was resumed, leading to a gradual recovery of hemoglobin levels to 109 g/L within two weeks, along with the resolution of cough and fatigue. This case highlights the effectiveness of roxadustat in managing anemia in dialysis patients, even in the context of Omicron virus infection.