The accuracy of pulse oximeters in diagnosing hypoxemia, especially in COVID-19 and other viral pneumonia cases, still needs to be determined despite their critical role in monitoring COVID-19 patients. This study aimed to assess the dependability of pulse oximeters in accurately detecting hypoxemia in individuals with COVID-19 pneumonia. A study was undertaken on 40 patients with COVID-19 pneumonia, in which pulse oximeter results were compared to arterial blood gas (ABG) analysis. The results of our study demonstrate a continuous overestimation of 1.77% in pulse oximetry values compared to arterial blood gas (ABG) measurements. When the threshold for SpO2 was set at less than 90%, the sensitivity and specificity were found to be 50% and 76.09%, respectively. These values slightly improved when the threshold was set at less than 92% for SpO2. The findings underscore notable constraints in utilizing pulse oximetry to identify low oxygen levels in COVID-19 pneumonia patients. This emphasizes the importance of interpreting oximeter values cautiously and advocating for more precise techniques, such as arterial blood gas (ABG) measurement, in severe situations.