Abstract: Raised levels of D-dimer have been noted in patients with COVID-19. The existing evidence emplies that the highest levels of D-dimer in the critically ill Covid-19 patient shows a linear relationship between the D-dimer measurement and the severity of the disease. However, that should also mean a patient on the road to recovery would have decrease in pro-thrombotic state and hence lower D-dimer readings. This study hypothesized that D-dimer trend would start to return towards normal as patients recovered from this illness. The present study included 43 patients with COVID-19 infection treated in the ICU at Khoula Hospital, Muscat, Oman from 10th May to 5th August 2020. Six readings of D-dimer were taken from the time of admission of Covid-19 npatient to their discharge from the ICU or demise. The data was statistically analyzed using generalized linear model, paired ‘t’ test and Wilcoxon Signet Ranks test. D-dimer demonstrated a statistically significant difference by the value of 4 μg/ml in patients who were eventually extubated compared to those who died while in the ICU, despite that, as a trend over time was insignificant. In conclusion, this study suggests that D-dimer would be noteworthy in assessing severity as a single time-point, however not as a prognostic value in evaluating improvement of critically ill patients of COVID-19.