Objectives: To analyze the added value of a new CXR scoring system in the evaluation of the COVID-19 pneumonia severity. Methods: This retrospective study included, from March to April 2020, 169 (132M/37F) hospitalized COVID-19 patients, mean age 65.6±10.8 years; 57 had low-pressure ventilation (Group A), 50 positive-pressure ventilation (Group B) and 62 invasive ventilation (Group C). Two radiologists in consensus evaluated the CXRs using an 18-points scoring system. CXR scores were compared in each Group and among the three Groups. Then in each Group CXR scores were correlated with Pa02/Fi02 and, in Group C, with Simplified Acute Physiology Score (SAPS). Non-parametric tests were used. Results: In Group A the median score at admission was 8 [Interquartile range (IR) 7-9] and the median of the highest scores was 9 [IR 8-10](p=0.0738). Median scores at admission and before the start of the ventilation (pre-ventilation) are resulted, in Group B, 10 [IR 8-10] and 11 [IR 10-14](p<0.0001) and, in Group C, 10 [IR 8-11] and 12 [IR 11-13](p<0.0001). In Group A the CXR scores at admission were lower than in Group C (p=0.0257), and the highest scores were lower than the pre-ventilation ones of Groups B (p=0.0018) and C (p=0.0001). The CXR scores correlated negatively with Pa02/Fi02 and positively with SAPS. Conclusion: CXR scoring system could be an added value in the evaluation of COVID-19 pneumonia severity. With lowpressure ventilation, the CXR scores were lower than with positive-pressure and invasive ventilation. Furthermore, CXR scores showed negative correlation with Pa02/Fi02 and positive with SAPS. Implications for practice: This new CXR scoring system could be a useful diagnostic tool to quantify the COVID-19 pneumonia severity and to guide to choice of the correct ventilation support.