Objective: We aimed to compare laboratory and outcome of the patients who were hospitalized in the intensive care unit with the diagnosis of Coronavirus Disease-19 (COVID-19) and transfused convalescent plasma based on timing of treatment. Methods: Patients administered 200 mL of convalescent plasma were analysed retrospectively. Based on symptoms’ onset, patients were divided into two groups as early (≤ 7 days) and late (> 7 days) plasma treatment groups. Patients’ characteristics, comorbidities, treatments, laboratory (pre-transfusion, day 1 and day 3 after transfusion) and outcome were evaluated according to groups. Results: A total of 152 patients matched criteria. There was no difference between the early (n=82) and late (n=70) treatment groups in terms of demographic characteristics, comorbidities, treatments, outcomes. Ferritin levels were higher in the early treatment group than in the late treatment group on before transfusion and day 1 (p=0.023, p=0.015). C reactive protein value was lower in the late treatment group on day 3 (p=0.011). Comparing the rate of change between day 1 and day 3 of treatment, it was observed that the changes in ferritin and fibrinogen values were higher in the late group than in the early group (p=0.014, p=0.049). There was no difference between the groups in other laboratory values and outcome. Conclusion: In our study, we observed that the timing of convalescent plasma had no significant effect on outcome. However, more evidence was needed to prove the difference in laboratory results. Keywords: Intensive care unit, COVID-19, convalescent plasma, mortality