Bladder dysfunction in myelodysplasia may present a significant hazard to the upper tract and a threat to kidney function. Urodynamic features of high leak pressure and detrusor-sphincter dyssynergia have been associated with an increased risk. We have developed an objective score to describe urodynamic findings in myelodysplasia. The score includes consideration of bladder compliance, detrusor contractility and reflux, in addition to leak pressure and sphincter behavior. In 171 myelodysplastic patients a significant correlation was demonstrated between the score and upper tract studies at the time of urodynamics and the score and the management decision. Of 73 myelodysplasia patients with normal upper tracts at the first urodynamics study hydronephrosis later developed in 14. The score was a potent predictor of outcome (p = 0.0006).