Impaired balance control is a common symptom of vestibular deficiencies. The Romberg test is one of the most commonly used balance tests in clinics. It allows clinicians to assess the subject's reaction posture control while standing. However, a positive Romberg test still relies on manual observation by the physician. It leads to technical issues in subjective evaluation during the test. The study aimed to propose an instrumented Romberg test using inertial measurement units (IMUs) to extract kinematic variables for objective assessment. Eighteen patients and thirteen healthy people participated in this study. They performed the Romberg test with their eyes closed, wearing IMU s at their head and pelvis. Six types of parameters are extracted from IMU s, such as maximum, average, and root mean square, Attenuation coefficients, sway velocity, and displacement. The results show that the patient group performed a larger sway in the lateral direction of head or pelvis level, where the maximum and RMS values have significant differences (p < 0.05) and large effect (Cohen's d > 0.8). The proposed approach can distinguish patients with vestibular dysfunction from healthy people and support objective clinical assessment.