Purpose: Evidence base to support use of the effortful swallow in clinical populations with dysphagia is currently lacking. This study aims to quantify the effects of effortful swallowing on pharyngeal swallowing biomechanics in adults with dysphagia using pharyngeal high-resolution manometry (PHRM).Method: ManoScan HRM equipment with a 4.2 mm pressure catheter was used.Participants completed duplicate 10ml baseline and 10ml effortful liquid (IDDSI Level 0) swallows in randomized order. PHRM data were analysed using a semiautomated online platform (www.swallowgateway.com).Result: Fifteen adults (8 males; range 45-86 years) with mixed aetiology dysphagia (Functional Oral Intake Scale Level 2-5) were included. Median pharyngeal contractile (156.81 mmHg cm s; IQR 80.62) increased significantly (213.50 mmHg cm s; IQR 117.2) during effortful swallowing (p = 0.002). Significant increases were also observed in velopharyngeal pressure (p = 0.001), mesopharyngeal pressure (p = 0.027), hypopharyngeal pressure (p = 0.003) and UOS relaxation duration (p = 0.002). UOS IRP was not significantly altered with effortful swallowing (p = 0.233). Conclusion:Effortful swallowing induced significant biomechanical changes to swallowing in adults with dysphagia. Increases in global pharyngeal rigor, tongue base pressure and UOS opening duration were captured by PHRM during effortful swallowing. Further investigation in larger homogeneous clinical populations is needed to verify the physiological effects of this frequently employed intervention.