AIM AND BACKGROUND: In the emergency department (ED), endotracheal intubation (ETI) is a critical, life-saving procedure. The MACOCHA score predicts difficult intubations in intensive care units (ICUs), but it has not been validated in the ED setting. This study aimed to validate the MACOCHA score for predicting first-pass success of ETI performed in the ED. MATERIALS AND METHODS: This prospective observational study was performed in the ED of a tertiary care institute, over a period of 18 months (September 2020 to February 2022). The study included 74 adult patients who underwent emergency ETI performed by emergency medicine residents. Number of ETI attempts, first-pass success rate, and complications were noted. The MACOCHA score was calculated, and its predictive performance was evaluated. RESULTS: The first-pass success rate was 54.1%, and 54.1% of patients experienced complications, with hypoxia (18.9%) and hypotension (17.6%) being the most common. Four ETI attempts ( CONCLUSION: MACOCHA score demonstrated limited performance in predicting the first-pass success rate of ETI in the ED. HOW TO CITE THIS ARTICLE: Shukla K, Bhardwaj BB, Kabi A, Galagali S, Manchanda H, Joshi S,