OBJECTIVE: In this study, we aimed to investigate the risk factors that may affect the prognosis and length of hospital stay of COVID-19 patients. particularly immunoglobulin A. MATERIALS AND METHODS: Patients admitted to the relevant department or intensive care unit with a diagnosis of COVID-19 between April 2020 and January 2021 were included in the study. Demographic characteristics of the patients and blood type. immunoglobulin A (IgA). C-reactive protein, D-dimer, procalcitonin, ferntin, troponin I, complete blood count, biochemical, and COVID-19 (SARS-CoV-2) reverse transcription polymerase chain reaction test results were evaluated retrospectively from the hospital files and data system. RESULTS: A total of 164 COVID-19 patients were included in this study. The median age was 72 (range: 30-95) years and the gender distribution of women and men was 66/98 (40.2% vs. 59.8%, respectively). There was no statistically significant relationship between blood type and hospitalization time or mortality (p=0.497 and p=0.923. respectively). There was furthermore no statistically significant relationship between Rh group and the duration of hospitalization or prognosis (p=0.198 and p=0.827. respectively). There was no statistically significant correlation between IgA level and hospitalization time or prognosis (p=0.066. r=0.144). In the analysis of defined risk factors independently associated with death. the following were found to be significant indicators of mortality: leukopenia [beta: -2.973. OR (95% CI): 0.051 (0.003-0.891). p=0.041], glucose [beta: 0.014, OR (95% CI): 1.014 (1.001-1.028). p=0.037], D-dimer [beta: 0.001, OR (95% CI): 1.001 (1.000-1.001), p=0.023]. duration of hospitalization [beta: -0.218, OR (95% CI): 0.804 (0.708-0.913), p=0.001], and duration of stay in the intensive care unit [beta: 0.348, OR (95% CI): 1.416 (1.186-1.690). p<0.001]. CONCLUSIONS: In our study, no relationship was found between IgA level and hospitalization time or mortality among COVID-19 patients. However, leukopenia and increased glucose. D-dimer, neutrophil count. urea. and durations of hospital and intensive care stays were found to be important predictors of mortality.