BACKGROUND: Timed barium swallow (TBS) is a simple non-invasive diagnostic test to evaluate esophageal emptying of liquids. TBS was originally described for the assessment of response to treatment in achalasia patients. Since then, its use has been expanded, including assessment of dysphagia in other esophageal motility disorders. OBJECTIVES: To provide a clinical review summarizing the main indications, protocol, interpretation and complementary role of TBS in the diagnosis of esophageal motility disorders. METHODS: A working group of gastroenterologists specialized in neurogastroenterology and motility disorders and radiologist reviewed the relevant medical literature on TBS. RESULTS: TBS provides an objective measure of esophagogastric junction (EGJ) opening and esophageal clearance. It is a useful diagnostic tool in achalasia, assessing the severity of EGJ obstruction and response to treatment. TBS complements high-resolution manometry (HRM) in symptomatic EGJ outflow obstruction (EGJOO) to help determining a need for treatment. TBS may also play a role in the assessment of absent contractility and other hypomotility disorders. TBS adds objective data on esophageal emptying which can aid decision-making when HRM is unclear or unavailable. CONCLUSIONS: TBS is a simple non-invasive diagnostic test for the evaluation of esophageal dysfunction. In achalasia and EGJOO, combined with a clinical evaluation and HRM findings, TBS provides valuable additional data and can guide treatment decisions.