Background: The global pandemic of corona virus disease 2019 (COVID-19) still growing and its death toll has been progressing massively as well disregarding the human and financial resources. This necessitates early detection of severe cases and treats them promptly. Thus, in this study, we aimed at identification of predictors of deterioration of mild cases of COVID-19. Methods: In this case control study, we included 137 subjects with confirmed COVID-19 from Suez Canal University Hospital. Baseline characteristics, laboratory and radiological data were documented. These variables were compared between those who witnessed deterioration (cases) and those who did not (control). Logistic regression analysis was performed to identify predictors of deterioration. Results: Fifteen out of 137 patients experienced clinical deterioration. Age, marital status, smoking status, diabetes mellitus (DM), hypertension, chronic pulmonary disease and chronic liver disease (CLD), and high mean of computed topography (CT score) were more prevalent among deteriorated patients; nevertheless, anosmia and loss of taste were characteristic of non-deteriorated cases. The latter group had relatively low mean lymphocytes, neutrophils/lymphocytes ratio (N/L ratio), albumin, and high mean of inflammatory markers. Logistic regression revealed that only diabetes, chronic liver disease, albumin, LDH, CT score were significant predictors of deterioration.Analysis of the receiver operating characteristic curve revealed that CT score was the most sensitive and specific indicator for prediction of deterioration. Conclusions: Many clinical data, laboratory and radiological features were more prominent in deteriorated cases, but DM, CLD, albumin, LDH and CT score were significant predictors of deterioration.