Introduction: Accumulating evidence indicates that inflammatory responses play a major role in the development and/or severity of coronavirus disease 2019 (COVID-19). Therefore, a retrospective, cross-sectional study was performed to provide an inflammatory profile in COVID-19. Methods: The study included 139 patients infected with COVID-19, who were admitted to inpatient wards and intensive care units in Baghdad Teaching Hospital. There were 105 patients suffering from non-severe illness and 34 patients had severe disease. This study simultaneously evaluated six peripheral blood markers of inflammation to determine their predictive value in COVID-19 severity. These were C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, D-dimer, lactate dehydrogenase (LDH) and neutrophil-to-lymphocyte ratio (NLR). Results: The medians of age, CRP, ESR, ferritin, D-dimer and NLR were significantly elevated in severe cases of COVID-19 compared to non-severe cases. The LDH also tended to have increased levels in severe cases but the difference was not significant compared to non-severe cases. Logistic regression analysis demonstrated that D-dimer was the most significant risk factor, followed by NLR, ferritin and CRP. Receiver operating characteristic (ROC) curve analysis identified that the best cut-off values of CRP, ESR, ferritin, D-dimer, LDH and NLR for predicting severity in COVID-19 patients were 22.7 mg/L, 59.5 mm/h, 719.4 ng/mL, 367.5 ng/mL, 468.5 U/L and 12.9, respectively. Conclusion: Age and the inflammatory markers CRP, ESR, ferritin, D-dimer, and NLR showed higher medians in severe cases of COVID-19 compared to non-severe cases. In this context, D-dimer and NLR are suggested to be important predictive markers of severe disease.