Purpose Hypernasality, which is a symptom of dysarthria, may be seen in patients with Myasthenia Gravis with bulbar symptoms. However, there is not enough evidence to show that these patients may have velopharyngeal dysfunction. This study investigates the features of velopharyngeal function in myasthenia gravis patients using objective and subjective measurement tools. Methods Ten adult myasthenia gravis patients with bulbar symptoms and ten adult myasthenia gravis patients without bulbar symptoms were recruited for this study. Ten healthy subjects were also included as the control group. The nasalance scores of the participants were determined using a nasometer. The degree and pattern of velopharyngeal closure were scored using flexible nasoendoscopy during speech, blowing, dry swallowing, and food swallowing. Perceptual hypernasality was assessed. Results Velopharyngeal dysfunction was detected in 50% of the myasthenia gravis patients with bulbar symptoms. Velopharyngeal dysfunction was not seen in myasthenia gravis patients without bulbar symptoms. The degree of velopharyngeal closure in patients with bulbar symptoms differed depending on the tasks being performed. No significant difference in velopharyngeal closure patterns was observed between the groups (p < 0.05). Conclusion Myasthenia gravis patients with bulbar involvement may have velopharyngeal dysfunction. It is important to conduct a comprehensive evaluation to assess all aspects of the velopharyngeal function.