Obstructive sleep apnea (OSA) is an important health problem associated with significant morbidity and mortality. This condition often is underrecognized in hospitalized patients. The aim of this study was to conduct a clinical pathway evaluation (CPE) among obese patients admitted to a tertiary care hospital. We also assessed oxygen desaturation index (ODI, measured by overnight pulse oximetry) as a potential low-cost screening tool for identifying OSA. This was a prospective study of 754 patients admitted to an academic medical center between February 2013 and February 2014. Consecutive obese patients (body mass index ≥ 30) admitted to the hospital (medical services) were screened and evaluated for OSA with the snoring, tiredness during daytime, observed apnea, high blood pressure (STOP) questionnaire. The admitting team was advised to perform follow-up evaluation, including polysomnography, if the test was positive. A total of 636 patients were classified as high risk and 118 as low risk for OSA. Within 4 w of discharge, 149 patients underwent polysomnography, and of these, 87% (129) were shown to have OSA. An optimal screening cutoff point for OSA (apnea-hypopnea index ≥ 10/h) was determined to be ODI ≥ 10/h [Matthews correlation coefficient = 0.36, 95% confidence interval = 0.24-0.47]. Significantly more hospitalized patients were identified and underwent polysomnography compared with the year prior to introduction of the CPE. Our results indicate that the CPE increased the identification of OSA in this population. Furthermore, ODI derived from overnight pulse oximetry may be a cost-effective strategy to screen for OSA in hospitalized patients.