Background: In December 2019, a new pathogen, HCoV, or New Corona Virus 2019 (2019-nCoV), was recognized in Wuhan, China, causing a pandemic. COVID-19 has a wide range of clinical severity. Approximately 3.2% of patients within some periods of the disease require intubation and invasive ventilation. Methods: This study was descriptive-analytical and was conducted in the Imam Khomeini Hospital. Patients with Covid-19 who required endotracheal intubation were identified and their clinical signs and laboratory parameters were recorded. SPSS23 software was used for statistical analysis. Results: 120 patients with coronavirus with different conditions were evaluated. The mean age was 55±14. 30 patients had cardiovascular disease (hypertension) and 20 endocrine disease(diabetes). Respiratory acidosis, decreased oxygen saturation, lymphopenia, and increased CRP were the most common finding before intubation. 31 patients had no comorbidity conditions. However, 27 patients had more than one comorbidity condition, and 23 experienced acute respiratory distress syndrome. The mortality rate was 49.2%. Discussion: Although all laboratory parameters and patients symptoms can affect the treatment outcome, it was found that WBC and absolute lymphocyte count, BUN, SOFA and APACHE scores, inflammatory index ratio CRP / LDH % CRP / ESR% and ESR / LDH%, arterial blood gas indices, pulse rate, and patient temperature before intubation are among the parameters that can affect the patient's 14-day prognosis. Conclusion: Except for the mentioned items, CRP / LDH% ratio seems to be a good indicator for checking the prognosis of discharge or death of patients within 14 days, However, CRP / ESR% and ESR / LDH% are appropriate criteria for determining the prognosis for discharge or stay in the ICU for more than 14 days.