Background: The coronavirus disease (COVID-19) was first found in Wuhan, China, on the 31st of December 2019. The spread has imposed changes in the world. Preceding studies have reported myriad laboratory values that may predict mortality in COVID-19 patients. Hence, this research aims to analyze routine laboratory testing results that can be used as a predictor of COVID-19 mortality to reduce complications, further disease progression, and in-hospital mortality  Method: This is an analytical observational retrospective study conducted at Universitas Airlangga Hospital, Surabaya, that analyzed patients demographic and laboratory results with the mortality of COVID-19 patients in the ICU from January to June 2021. Total consecutive sampling was conducted on patients aged 18 and above with a confirmed COVID-19 diagnosis.  Results: From a total of 116 patients included in this study, 71 were deceased, with a mortality rate of 61.2%. Univariate logistic regression reveals that D-dimer levels on admission with a cut-off point of > 2000 ng/mL  were associated with mortality and positively correlated with COVID-19 mortality (OR [95%]: 2.684 [1.177-6.122] p= 0.019).  Conclusion: Elevated D-dimer at admission (>2000 ng/mL) should be used as a predictor of COVID-19 mortality to decrease the risk of complications and decrease in-hospital mortality.