The age group at the most high risk for mortality due to SARS-CoV-2 infection was the elderly. This study aims to analyze markers that can predict the severity and mortality of elderly COVID-19 patients. This study used a cohort retrospective design. We include adult and elderly COVID-19 patients at Universitas Airlangga Hospital from March to August 2021. The sample used was 48 COVID-19 patients with positive real-time polymerase chain reaction swab results. We check the complete blood count and serum levels of interleukin-6 (IL-6) and IL-10 using enzyme-linked immunosorbent assay during admission. Data were analyzed using t -test, Mann-Whitney, Chi-square, Pearson, and Kendall Tau correlation. Leukocyte level (6.6 ± 2.5) was lowest in the severe-critical elderly group. Neutrophil level (75.3 ± 10.2) was highest in the mild-moderate elderly group. Lymphocyte level (18.8 ± 8.7) was highest in mild-moderate nonelderly group. Platelet level (279.0 ± 117.7) was highest in the mild-moderate elderly group. Neutrophil to lymphocyte ratio level (9.1 ± 9.4) was highest in the severe-critical nonelderly group, IL-6 level (98.6 ± 144.1) was highest in the severe-critical elderly group, IL-10 level (107.7 ± 47.7) was highest in the severe-critical elderly group and highest IL-6/IL-10 level (1.4 ± 1.7) was found in the mild-moderate elderly group no significant differences in biomarkers identification between the elderly and nonelderly groups. There was a substantial relationship between IL-10 levels and gender, IL-10 level, and hospital discharge condition. Female elderly patients and alive elderly patients were correlated with increased levels of IL-10.