BACKGROUND: Limited attention has been paid to the relationship between bladder dysfunction and motor disorder in multiple system atrophy (MSA). OBJECTIVE: We aimed to correlate pressure-flow urodynamic parameters with video-gait analysis parameters in MSA. METHODS: We recruited 34 patients with MSA: 20 men, 14 women; age 64.0 + - 7.9 years; disease duration 2 years (1-4 years). Nineteen cases had the cerebellar form, and 15 had the parkinsonian form; the patients were taking levodopa 300 mg/day (100-400 mg). All patients underwent pressure-flow urodynamics (parameters: detrusor overactivity [noted in 72%] and Watts factor) and video-gait analysis (parameters: time and the number of strides taken to walk 5 m (simple task) and time for timed up and go (complex task). Statistical analysis was done using Student's t-test to analyze the relation between detrusor overactivity and gait, and Spearman's rank correlation coefficient test to analyze the relation between the remaining parameters and gait. RESULTS: We found no relation between filling-phase urodynamics (detrusor overactivity) and video-gait analysis parameters. Also, we found no relation between voiding-phase urodynamics (Watts factor, reflecting detrusor power) and all three video-gait analysis parameters in our MSA patients. CONCLUSION: The fact that neither detrusor overactivity nor the Watts factor was related with motor disorders in the present study suggests that bladder dysfunction occurs independently from motor disorder in MSA.