Neurourological studies were performed on 39 patients with cervical myelopathy due to ossification of the posterior longitudinal ligament. Micturitional history revealed that 30 patients (77%) had voiding symptoms: obstructive in 8, irritative in 11, and both obstructive and irritative symptoms in 11. Ten patients had urge incontinence and 4 had urinary retention. Urodynamic studies revealed that 7 of 19 had abnormal uroflowmetrogram, 16 of 35 had residual urine, 18 of 39 had detrusor hyperreflexia, and 10 of 39 had detrusor-sphincter dyssynergia. There were no statistical differences in lower extremity neurological signs in patients with incontinence, and patients with residual urine or urinary retention.