A complete urodynamic study was carried out on 41 consecutive patients presenting in the cystomanometry a vesical filling pressure at maximum capacity higher than 30 cm H2O. Two groups were evident: group I with neurogenic etiology, and group II without an obvious neurogenic etiology. From its results it can be seen that a diminished vesical accommodation is not a urodynamic fact restricted to vesicourethral neurogenic dysfunction, but it happens in several non-neurogenic conditions. Within the neurogenic group, the urodynamic element most frequently associated to a diminished vesical accommodation was an inferior motor neuron-like vesicourethral dysfunction. An increased vesical filling pressure was not enough to produce urinary incontinence, being also necessary an added factor to prompt involuntary loss of urine.