Introduction: Pneumonia, also known as pneumonia, is caused by inflammation of the air sacs (alveoli) in one or both lungs. In severe pneumonia, intravascular and intra-alveolar coagulation occurs, which is a response to local and systemic inflammatory processes. The clinical consequence of these changes in coagulation is an increase in the level of D-Dimer which causes death. The purpose of this study was to evaluate D-Dimer in 29 pneumonia patients and 37 COVID-19 patients at Jemursari Hospital. Methods: This research is quantitative with a cross-sectional analytic observational method. The research sample was obtained from the Jemursari Islamic Hospital in Surabaya for pneumonia and Covid-19 patients in 2021 Results: The results of the study, a number of women more than men. In women 63,6% and in men 36,4%, while the age is 46-54 years in pneumonia patients 28% and in Covid-19 patients 30%. D-Dimer levels in pneumonia patients 1001-2000 ng/mL were 35% higher compared to COVID-19 patients 501-1000 ng/mL were 30%. Mann Whitney's non-parametric test results obtained p=0.041 (p<0.05), meaning that there was a difference in D-Dimer levels between pneumonia patients and COVID-19. Conclusion: D-Dimer levels were more elevated in pneumonia patients than in Covid-19, so Covid-19 infection did not exacerbate coagulation and fibrinolysis activities.