Background. Patients with coronavirus disease 2019 (COVID-19) experience a wide clinical spectrum, with over 2% developing fatal outcome. The prognostic factors for fatal outcome remain sparsely investigated. Methods. A retrospective cohort study was performed in a cohort of patients with confirmed COVID-19 in one designated hospital in Wuhan, China, from 17 January-5 March 2020. The laboratory parameters and a panel of cytokines were consecutively evaluated until patients' discharge or death. The laboratory features that could be used to predict fatal outcome were identified. Results. Consecutively collected data on 55 laboratory parameters and cytokines from 642 patients with COVID-19 were profiled along the entire disease course, based on which 3 clinical stages (acute stage, days 1-9; critical stage, days 10-15; and convalescence stage, day 15 to observation end) were determined. Laboratory findings based on 75 deceased and 357 discharged patients revealed that, at the acute stage, fatality could be predicted by older age and abnormal lactate dehydrogenase (LDH), urea, lymphocyte count, and procalcitonin (PCT) level. At the critical stage, the fatal outcome could be predicted by age and abnormal PCT, LDH, cholinesterase, lymphocyte count, and monocyte percentage. Interleukin 6 (IL-6) was remarkably elevated, with fatal cases having a more robust production than discharged cases across the whole observation period. LDH, PCT, lymphocytes, and IL-6 were considered highly important prognostic factors for COVID-19-related death. Conclusions. The identification of predictors that were routinely tested might allow early identification of patients at high risk of death for early aggressive intervention.